NL2024415B1

NL2024415B1 - Polysulfide sealant with improved cure time

Info

Publication number: NL2024415B1
Application number: NL2024415A
Authority: NL
Inventors: Maximilian Striewe Ludger; Frank De Block Rudolph
Original assignee: Strongbond B V
Priority date: 2019-12-10
Filing date: 2019-12-10
Publication date: 2021-08-31
Also published as: WO2021118340A1

Abstract

The present invention is in the field of an improved 2— component polysulfide sealant composition, use of said compo— sition, especially in or on locations which are preferably not closed, such as roads, and railways, on parking decks, and on 5 airfields. The adhesive composition has an improved cure time.

Description

Polysulfide sealant with improved cure time

FIELD OF THE INVENTION The present invention is in the field of an improved 2- component polysulfide sealant composition, use of said compo- sition, especially in or on locations which are preferably not closed, such as roads, and railways, on parking decks, and on airfields. The adhesive composition has an improved cure time.

BACKGROUND OF THE INVENTION Closing roads, railways, or airfield platforms for maintenance is very expensive, not to mention the nuisance it causes for both users as managers of the system. It is there- fore preferred that maintenance should be performed as less as possible by using long lasting materials and systems, and when maintenance 1s necessary the downtime is best minimized.

Polysulfide sealants have superior elasticity and dura- bility over any bitumen-based materials. Due to their sulfur content they have a pseudoplastic character which allows to reduce and annihilate internal constant stresses which no oth- er known elastic sealant does. In addition, polysulfide seal- ants have constant movement tolerances of 25% or more (as de- fined in ISO 11600). It is therefore that lately there is a renewed interest in polysulfide sealants for the above appli- cation to replace bitumen-based sealants.

Bitumen based sealants do not really cure. They are mol- ten, applied in a liquid state, and after a cooling done peri- od, they are ready. The time it takes to melt the sealants and the energy costs are often ignored as the melting can be done beforehand. Polysulfide sealants on the other hand are applied at ambient temperature and cure by a chemical process, usually by oxidation with activated manganese dioxide, which is mixed in prior or during application. After the mix is applied it may take three hours or (much) longer for the sealant to cure. The exact curing time typically depends on the accelerators added and on the ambient temperature. However, a cure time of shorter than three hours is desired.

To those working in the application of these polysulfide sealants a little trick is known to increase the curing speed of the polysulfide sealant. This is done by adding a tiny amount of water to the mixture after or better during mixing of the sealant and the manganese dioxide containing curing agent. However, several strongly negative side effects are known by this use of free water. The rheology is jeopardized, the viscosity is increased, the flow decreased, and the cure of the surface of the sealant seems retarded, leading to a sticky surface which lasts for several hours. Due to the changes in rheology the water can not be added to any of the polysulfide components prior to mixing with the curing agent. Also, the water can only be added, and therefore is only use- ful, in hand mixed applications, wherein the sealant is mixed prior to application. Hand mixable mixtures are, however, al- ready slow reacting, and to include additional time between mixing and a curing state upon application is no longer possi- ble. This window if often referred to as the open time or ap- plication window. Another problem associated by adding a lit- tle water to the polysulfide sealant is the addition of too much water. This will lead to an inferior sealant. In machine applications, where both sealant and curing agent are mixed and applicated at the same time, usually by pumping both in the desired ratio through a stationary mixer, a further addition of e.g. water cannot be done. Not only there would be the technical difficulty of adding and mixing three components into one flow, but the low viscosity of water would leave mixing through a stationary mixer inadequate. Therefore, a solution to increase the curing speed of in particular machine applied polysulfides is strongly desired. It is therefore an object of the present invention to provide a polysulfide adhesive which overcomes one or more of the above disadvantages, without jeopardizing functionality and advantages.

SUMMARY OF THE INVENTION The present invention relates to 2-component polysul- fide sealant and use thereof. It has now been found that the above problems can be overcome by adding the water bounded in a physical or physical-chemical way, that is sorbed water, for example by addition of the water absorbed in a zeolite. The addition of water did not influence the viscosity, or not noticeable. When this zeolite is used in the form of a powder this zeolite will not negatively in-

fluence the rheology. Now the water can already be added during the production stage without having to worry about the amount of water added or any negative effect associated by the addition of water before. The product, including the bounded water, is storage stable. Surprisingly the rheology is no longer jeopardized and the surface tackiness does no longer occur. By addition of water in this bound form a relative increase in curing speed (and likewise reduction of curing time) of 20-30% is achieved.

The present 2-component polysulfide sealant comprises in the first component, 10-70 wt.% of a liquid polysulfide resin, preferably 20-60 wt.%, more preferably 30-50 wt.%, 5-20 wt.3 of at least one first plasticizer, preferably 7-18 wt.%, more preferably 10-15 wt.%, 5-40 wt.% a filler, preferably 10-35 wt.%, more preferably 20-30 wt.%, and optionally 0-5 wt.% sul- phur, preferably 0,2-4 wt.#%, more preferably 1-3 wt.%, 0-5 wt.% of an adhesion promotor, preferably 0.2-4 wt.%, more preferably 1-3 wt.%, 0-5 wt.% of a retarder, preferably 0.2-4 wt.%, more preferably 1-3 wt.%, 0-5 wt.% of a first dispersion agent, preferably 0.2-4 wt.3, more preferably 1-3 wt.%, and 0- 5 wt.% of at least one further additive, preferably 0.2-4 wt.%, more preferably 1-3 wt.%, in the second component 1-5 wt.4 of a curing agent, preferably 2-4 wt.3, more preferably

2.5-3 wt.%, such as manganese oxide; 1-5 wt.% of a second plasticizer, preferably 2-4 wt.%, more preferably 2.5-3 wt.$%, and optionally 0-5 wt.% of a rheology modifier, preferably

0.2-4 wt.%, more preferably 1-3 wt.%, 0-5 wt.% of an accelera- tor, preferably 0.2-4 wt.%, more preferably 1-3 wt.%, 0-5 wt.% of sulphur, preferably 0.2-4 wt.%, more preferably 1-3 wt.3, 0-5 wt.% of a second dispersion agent, preferably 0.2-4 wt.%, more preferably 1-3 wt.%, and 0.01-5 wt.% porous material, preferably 0.02-4 wt.3, more preferably 0.1-3 wt.%, even more preferably 0.3-2.5 wt.%, such as 0.4-2 wt.%, e.g. 0.7-1.4 wt.%, such as zeolite, and sorbed water, preferably 0.02-4 wt.3, more preferably 0.1-3 wt.%, even more preferably 0.3-2.5 wt.4, such as 0.4-2 wt.%, e.g. 0.7-1.4 wt.%, wherein all weight percentages are based on a total weight of the 2- component adhesive.

In a second aspect the present invention relates to the use of the present adhesive for increased curing speed, for machine applying, in trafficable surfaces, such as roads, and railways, on parking decks, and on airfields. Thereby the present invention provides a solution to one or more of the above-mentioned problems.

Advantages of the present description are detailed throughout the description.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates in a first aspect to a composition according to claim 1.

In an example of the present composition the water may be sorbed in the porous material, such as in the zeolite.

In an example of the present composition the porous ma- terial may be provided as particles in powder form with an av- erage particles size of <100 um, preferably from 1-60 um, more preferably 10-50 um, even more preferably 15-40 pm, such as 20-30 um.

In an example of the present composition the porous ma- terial may have an open pore volume of 30-70 vol.%, based on the total volume of the porous material.

In an example of the present composition an average pore size may be from 0.25-2.1 nm (2.5-21 A), preferably from

0.26-1.5 nm (2.6-15 A), more preferably 0.27-1.2 nm (2.7-12 A), even more preferably from 0.29-1.0 nm (2.9-10 A), such as from 0.3-0.7 nm (3.0-7 A.

In an example of the present composition the porous ma- terial may be grinded, milled, sieved, and combinations there- of.

In an example of the present composition the filler may be selected from chalk, precipitated chalk, coated precipitat- ed chalk, silica, alumina, carbon black, and combinations thereof.

In an example of the present composition the first and second plasticizer each individually may be selected from ben- zoic acid esters, phthalic acid diesters, terephthalic acid diesters, chlorinated paraffins with a chain length >C8, ben- zoates, phthalates, terephthalates, polyols, hydrogenated ver-

sions of phthalates, terephthalates and benzoates, and combi- nations thereof.

In an example of the present composition the additives may be selected from catalysts, co-catalysts, rheology control 5 agents, pigments, pigment pastes, HALS, UV stabilizers, anti- oxidants, adhesion promotors, drying agents.

In an example of the present composition the adhesion promotor may be selected from epoxy resins and glycidyltri- methoxysilane.

In an example of the present composition the first and second accelerator each individually may be selected from di- alkyl thiurams with Cl to C7 alkyl, Cl to C7 aryl, or Cl to C7 alkaryl groups, metal-dialkyldithiocarbamates, with the metal preferably zinc, and with Cl to C7 alkyl, Cl to C7 aryl, or Cl to C7 alkaryl groups, mercaptobenzthiazole, and metal salts thereof, the metal being preferably zinc.

In an example of the present composition the retarder may be selected from branched, unbranched, saturated, and un- saturated organic acids with a chain length of 8-20 carbons, and combinations thereof, such as isostearinic acid.

In an example of the present composition the first dis- persion agent may be selected from phosphoric acid polyesters.

In an example of the present composition the second dispersion agent may be selected from fatty alcohol esters, such as alcohol esters with >7 carbons.

In an example of the present composition the rheology modifier may be selected from fumed silica, carbon black, and polyamide waxes, and combinations thereof.

In an example of the present composition the zeolite may be selected from CaA zeolites, CaX zeolites, NaX zeolites, NaY zeolites, and a natural zeolite of Nickel-Strunz class

09.G.

In an example of the present composition the first and second component may be provided in a weight ratio of 40:1 to

0.5:1, preferably 30:1 to 0.6:1, more preferably 25:1 to

0.7:1, such as 20:1 to 2:1.

In an example of the present composition the present composition may comprise a combination of the above.

The invention is further detailed by the accompanying figures and examples, which are exemplary and explanatory of nature and are not limiting the scope of the invention. To the person skilled in the art it may be clear that many variants, being obvious or not, may be conceivable falling within the scope of protection, defined by the present claims.

FIGURES Figure 1: The curing of the poly sulphide sealants is determined by an oscillation test on the Anton Pair MC302 Rheometer. By setting the storage modulus against time, the curing speed of the sealant can be determined. Figure 2 Comparison of viscosities at different Shear rates of the B-side component of a poly sulphide kit with hydrated zeolite and with water. Water thickening of the kit in the low shear rates clearly increases. EXAMPLES/EXPERIMENTS The invention although described in detailed explana- tory context may be best understood in conjunction with the accompanying examples. During the development of a faster Sealer Fast (IPPB 1802 Faster Sealer Fast) it was noticed that the PS reaction could be significantly accelerated by adding hydrated zeolite. It was found that when water is added in pure form, this has a negative influence on the self-levelling capacity of the poly- sulfides. With water in zeolite this seemed to be less the case. Experiments To confirm that the B-side with hydrated zeolite flows better than with water addition, rheology tests were done. These have also been used to determine the curing of the seal- ant. For this purpose, the mixed A and B components were meas- ured at a shear strain of 0.03% and a frequency of 1Hz. In these rheology measurements it was first determined at which water content in the B-side the same speed is reached as with an addition of 1.5% hydrated zeolite in part B. After- wards the viscosities at different Shear rates were compared with each other.

Results In the amount of zeolite used are based on the total for- mula 0.25% water is present. Therefore, for the tests a water content of 0.25% and a tenth thereof were chosen.

Figure 1 shows that at a water content of 0.025% water in the B-side the same speed could be achieved as with 1.5% of the hydrated zeolite. It also becomes clear that curing with- out water or zeolite is significantly slower and that a higher concentration of water will allow the sealant to cure even faster.

Figure 2 shows that the 0.025% water thickens the B-side in the low shear rates more than the zeolite. This can also be seen in the flow. The B-side with hydrated zeolite still flows well. The B-side with water no longer flows and can therefore no longer be used in the application of the Saba Sealer Fast. Conclusion This research has proven that the wet zeolite in the B- side of the Saba Sealer Fast, at the same acceleration of the system, thickens the component less than water.

It should be appreciated that for commercial application it may be preferable to use one or more variations of the pre- sent system, which would similar be to the ones disclosed in the present application and are within the spirit of the in- vention.

For the sake of searching the following section is added which represents embodiments of the invention and of which a translation is given into Dutch in the subsequent section.

1. A 2-component polysulfide sealant comprising in the first component, 10-70 wt.% of a liquid polysulfide resin, 5-20 wt.% of at least one first plasticizer, 5-40 wt.% a filler, and optionally 0-5 wt.% sulphur, 0-5 wt.% of an adhesion promotor, 0-5 wt.% of a retarder, 0-5 wt.% of a first dispersion agent, and 0-5 wt.3 of at least one further additive, in the second component 1-5 wt.% of a curing agent, such as manganese oxide;

1-5 wt.3 of a second plasticizer, and optionally 0-5 wt.?2 of a rheology modifier, 0-5 wt.% of an accelerator, 0-5 wt.% of sulphur, 0-5 wt.% of a second dispersion agent, and

0.01-5 wt.% porous material, such as zeolite, and sorbed water, wherein all weight percentages are based on a total weight of the 2-component adhesive.

2. Sealant according to embodiment 1, wherein the water is sorbed in the porous material, such as in the zeolite.

3. Sealant according to embodiment 2, wherein the porous ma- terial is provided as particles in powder form with an av- erage particles size of <100 um, preferably from 1-60 um, more preferably 10-50 um, even more preferably 15-40 pm, such as 20-30 um.

4. Sealant according to embodiment 2 or 3, wherein the porous material has an open pore volume of 30-70 vol.%, based on the total volume of the porous material.

5. Sealant according to any of embodiments 2-4, wherein an average pore size is from 0.25-2.1 nm (2.5-21 A), prefera- bly from 0.26-1.5 nm (2.6-15 A), more preferably 0.27-1.2 nm (2.7-12 A), even more preferably from 0.29-1.0 nm (2.9- 10 A), such as from 0.3-0.7 nm (3.0-7 A).

6. Sealant according to any of embodiments 2-5, wherein the porous material is grinded, milled, sieved, and combina- tions thereof.

7. Sealant according to any of embodiments 1-6, wherein the filler is selected from chalk, precipitated chalk, coated precipitated chalk, silica, alumina, carbon black, and combinations thereof.

8. Sealant according to any of embodiments 1-7, wherein the first and second plasticizer each individually are select- ed from benzoic acid esters, phthalic acid diesters, ter- ephthalic acid diesters, chlorinated paraffins with a chain length >C8, benzoates, phthalates, terephthalates, polyols, hydrogenated versions of phthalates, tereph- thalates and benzoates, and combinations thereof.

9. Sealant according to any of embodiments 1-8, wherein the additives are selected from catalysts, co-catalysts, rhe-

ology control agents, pigments, pigment pastes, HALS, UV stabilizers, antioxidants, adhesion promotors, and drying agents, and/or wherein the adhesion promotor is selected from epoxy resins and glycidyl trimethoxysilane, and/or wherein the first and second accelerator each individually are selected from dialkyl thiurams with Cl to C7 alkyl, C1 to C7 aryl, or Cl to C7 alkaryl groups, metal- dialkyldithiocarbamates, with the metal preferably zinc, and with C1 to C7 alkyl, Cl to C7 aryl, or Cl to C7 alkaryl groups, mercaptobenzthiazole, and metal salts thereof, the metal being preferably zinc, and/or wherein the retarder is selected from branched, unbranched, saturated, and unsaturated organic acids with a chain length of 8-20 carbons, and combinations thereof, such as iso- stearinic acid, and/or wherein the first dispersion agent is selected from phos- phoric acid polyesters, and/or wherein the second dispersion agent is selected from fatty alcohol esters, such as alcohol esters with >7 carbons, and/or wherein the rheclogy modifier is selected from fumed silica, carbon black, and polyamide waxes, and combinations thereof.

10. Sealant according to any of embodiments 2-9, wherein the zeolite is selected from CaA zeolites, CaX zeolites, NaX zeolites, NaY zeolites, and a natural zeolite of Nickel- Strunz class 09.G.

11. Sealant according to any of embodiments 1-10, wherein the first and second component are provided in a weight ratio of 40:1 to 0.5:1, preferably 30:1 to 0.6:1, more prefera- bly 25:1 to 0.7:1, such as 20:1 to 2:1.

12. Use of the sealant according to any of embodiments 1-11 for increased curing speed, for machine applying, in traf- ficable surfaces, such as roads, and railways, on parking decks, and on airfields.

Claims

CONCLUSIONS

A 2-component polysulfide sealant comprising in the first component, 10-70% by weight of a liquid polysulfide resin, 5-20% by weight of at least one first plasticizer, 5-40% by weight of a filler, and optionally 0-5 wt% sulfur, 0-5 wt% of an adhesion promoter, 0-5 wt% of a retarder, 0-5 wt% of a first dispersant, and 0-5 wt% of at least one other additive, in the second component 1-5% by weight of a curing agent such as manganese oxide; 1-5 wt% of a second plasticizer, and optionally 0-5 wt% of a rheology modifier, 0-5 wt% of an accelerator, 0-5 wt% sulfur, 0-5 wt% of a second dispersant, and 0.01-5 wt.3 porous material, such as zeolite, and sorbed water, all weight percentages based on a total weight of the 2-component sealant.

The sealant of claim 1, wherein the water is sorbed into the porous material, such as into the zeolite.

The sealant of claim 2, wherein the porous material is provided as powdered particles having an average particle size of <100 µm, preferably from 1-60 µm, more preferably 10-50 µm, more preferably 15-40 µm, such as 20-30 pm.

The sealant of claim 2 or 3, wherein the porous material has an open pore volume of 30-70 vol% based on the total volume of the porous material.

A sealant according to any one of claims 2-4, wherein the mean pore size is from 0.25-2.1 nm (2.5-21 ), preferably from 0.26-1.5 nm (2 .6-15 ), more preferably 0.27-1.2 nm (2.7-12 ), more preferably 0.29-1.0 nm (2.9-10 A), such as 0.3-0 .7 nm (3.0-7 ).

The sealant of any one of claims 2-5, wherein the porous material is milled, milled, sieved, and combinations thereof.

The sealant of any one of claims 1-6, wherein the filler is selected from chalk, precipitated chalk, coated precipitated chalk, silica, alumina, activated carbon, and combinations thereof.

A sealant according to any one of claims 1 to 7, wherein the first and second plasticizers are each individually selected from benzoic acid diesters, phthalic acid diesters, terephthalic acid diesters, chlorinated paraffins with a chain length >C8, benzoates, phthalates, terephthalates, polyols , hydrogenated versions of phthalates, terephthalates and benzoates, and combinations thereof.

A sealant according to any one of claims 1-8, wherein the additives are selected from catalysts, cocatalysts, rheology control agents, pigments, pigment pastes, HALS, UV stabilizers, antioxidants, adhesion promoters, and drying agents, and/or wherein the adhesion promoter is selected from epoxy resins and glycidyltrimethoxysilane, and/or wherein the first and second accelerators are each individually selected from dialkylthiurams having C1 to C7 alkyl, C1 to C7 aryl, C1 - to C7 alkaryl, metal dialkyldithiocarbamates, the metal preferably being zinc, and having C1 to C7 alkyl, C1 to C7 aryl, or C1 to C7 alkaryl groups, mercury benzthiazole, and metal salts, wherein the metal is preferably zinc, and/or wherein the retarder is selected from branched, linear, saturated, and unsaturated organic acids having a chain length of 8-20 carbons, and combinations thereof, such as isostearic acid, and/or wherein the first dispersant is selected from phosphoric acid polyesters, and/or wherein the second dispersant is selected from fatty alcohol esters, such as alcohol esters having more than 7 carbons, and/or wherein the rheology modifier is selected from fumed silica, activated carbon, and polyamide waxes, and combinations thereof.

10. A sealant according to any one of claims 2-9, wherein the zeolite is selected from CaA zeolites, CaX zeolites, NaX zeolites, NaX zeolites, NaY zeolites, and a natural Nickel-Srunz class 09 zeolite. g.

A sealant according to any one of claims 1-10, wherein the first and second components are provided in a weight ratio of 40:1 to 0.5:1, preferably 30:1 to 0.6:1, more preferably 25 :1 to 0.7:1, such as 20:1 to 2:1.

Use of the sealant according to any one of claims 1-11 for increased curing speed, for machine application, in traffic areas such as roads, and railways, on parking decks, and at airports.