Hot water resistant polymercaptan-based resin composition

Abstract

Disclosed is a resin composition comprising a polymercaptan hardener and an epoxy resin, a method for preparing the same and an adhesive, sealant, coating, or composite comprising the resin composition.

Description

[0001] 1 HAM-830230

[0002] HOT WATER RESISTANT POLYMERCAPTAN-BASED RESIN COMPOSITION Field of the invention

[0003]

[0001] The present disclosure relates to a polymercaptan-based resin composition having a high hot water resistance when cured. The resin composition is based on 3,3'-((2-((2-hydroxy-3 -mercaptopropoxy )methyl)-2-methylpropane-l, 3 -diyl)bis(oxy))bis(l-mercaptopropan-2-ol) as polymercaptan-based hardeners and at least one epoxy resin. The disclosure also related to 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol) or any polymercaptans containing this molecule as a substructure and methods for synthesising the same.

[0004] Background to the invention

[0005]

[0002] Resin compositions based on epoxy resins and polymercaptan hardener are commonly used as both adhesives, protective coatings and composites with applications across a range of industries including automotive, aerospace, freight, and the oil / gas industry. The ubiquitous use of epoxy resins arises from their good heat and chemical resistance, favourable mechanical properties, and good adhesion to a range of substrates.

[0006]

[0003] However, failure of the epoxy resin can result in joint failure and / or exposure of the underlying substrate to the environment making it vulnerable to corrosion and shortening the lifespan of the substrate. The cost of corrosion worldwide has been estimated to be US$2.5trillion. Unfortunately, it is not possible to completely stop moisture ingress. Moisture, in particular hot water has been found to decrease the adhesion of the resin, cause yellowing and cause cracking.

[0007]

[0004] Due to the high loss of adhesion and thermomechanical properties after exposure to hot water, commercial mercaptans (in particular, ester based mercaptans, such as trimethylolpropane trimercaptopropionate or pentaerythritol tetramercaptopropionate) are rarely used in structural applications.

[0008] Object of the disclosure

[0009]

[0005] It is therefore an object of the disclosure to provide polymercaptan hardeners for use in epoxy resin compositions that maintain good adhesion and thermomechanical properties after exposure to hot water. 2 HAM-830230

[0010]

[0006] In one aspect, the present disclosure provides 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol).

[0011]

[0007] In a further aspect of the disclosure is provided a resin composition comprising a hardener which is 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol) and at least one thiol reactive epoxy resin.

[0012]

[0008] In another aspect is provided a method for preparing 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol) comprising:

[0013] i) reacting epichlorohydrin with l,l,l-tris(hydroxymethyl)ethane to give the corresponding epoxy resin;

[0014] ii) reacting the resultant epoxy compound with H₂S gas or with thioacetic acid followed by deacetylation.

[0015] Detailed Description

[0016]

[0009] The present disclosure will be described with respect to particular aspects and embodiments.

[0017]

[0010] Unless otherwise defined herein, technical terms used in connection with the present disclosure shall have the meanings that are commonly understood by those having ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0018]

[0011] All patents, published patent applications, and non-patent publications mentioned in the specification are indicative of the level of skill of those skilled in the art to which the present disclosure pertains. All patents, published patent applications, and non-patent publications referenced in any portion of this application are herein expressly incorporated by reference in their entirety to the same extent as if each individual patent or publication was specifically and individually indicated to be incorporated by reference to the extent that they do not contradict the instant disclosure.

[0019]

[0012] All of the compositions and / or methods disclosed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of the present disclosure have been described in terms of preferred embodiments, it will be apparent to those having ordinary skill in the art that variations may be applied to the compositions and / or methods and in the steps or sequences of steps of the methods described herein without departing from the concept, spirit, and scope of the present disclosure. All such 3 HAM-830230

[0020] similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the present disclosure.

[0021]

[0013] As utilized in accordance with the present disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings.

[0022]

[0014] The use of the word “a” or “an”, when used in conjunction with the term “comprising”, “including”, “having”, or “containing” (or variations of such terms) may mean “one”, but it is also consistent with the meaning of “one or more”, “at least one”, and “one or more than one”.

[0023]

[0015] The use of the term “or” is used to mean “and / or” unless clearly indicated to refer solely to alternatives and only if the alternatives are mutually exclusive.

[0024]

[0016] Throughout this disclosure, the term “about” is used to indicate that a value includes the inherent variation of error for the quantifying device, mechanism, or method, or the inherent variation that exists among the subject(s) to be measured. For example, but not by way of limitation, when the term “about” is used, the designated value to which it refers may vary by plus or minus ten percent, or nine percent, or eight percent, or seven percent, or six percent, or five percent, or four percent, or three percent, or two percent, or one percent, or one or more fractions therebetween.

[0025]

[0017] As used herein, the term “substantially free” refers to a composition or blend in which a particular compound or moiety is present in an amount that has no material effect on the composition or blend. In some embodiments, “substantially free” may refer to a composition or blend in which the particular compound or moiety is present in the composition or blend in an amount of less than 2% by weight, or less than 1% by weight, or less than 0.5% by weight, or less than 0.1% by weight, or less than 0.05% by weight, or even less than 0.01% by weight, based on the total weight of the composition or blend, or that no amount of that particular compound or moiety is present in the respective composition or blend.

[0026]

[0018] The use of “at least one” will be understood to include one as well as any quantity more than one, including but not limited to, 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 100, etc. The term “at least one” may extend up to 100 or 1000 or more depending on the term to which it refers. In addition, the quantities of 100 / 1000 are not to be considered as limiting since lower or higher limits may also produce satisfactory results.

[0027]

[0019] As used herein, the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. 4 HAM-830230

[0028]

[0020] The phrases “or combinations thereof’ and “and combinations thereof’ as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof’ is intended to include at least one of A, B, C, AB, AC, BC, or ABC and, if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more items or terms such as BB, AAA, CC, AABB, AACC, ABCCCC, CBBAAA, CABBB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context. In the same light, the terms “or combinations thereof’ and “and combinations thereof’ when used with the phrases “selected from” or “selected from the group consisting of’ refers to all permutations and combinations of the listed items preceding the phrase.

[0029]

[0021] The phrases “in one embodiment,” “in an embodiment,” “according to one embodiment,” and the like generally mean the particular feature, structure, or characteristic following the phrase is included in at least one embodiment of the present disclosure and may be included in more than one embodiment of the present disclosure. Importantly, such phrases are non-limiting and do not necessarily refer to the same embodiment but, of course, can refer to one or more preceding and / or succeeding embodiments. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

[0030]

[0022] As used herein, the term “ambient temperature” refers to the temperature of the surrounding work environment (e.g., the temperature of the area, building or room where the curable system is used or produced), exclusive of any temperature changes induced by a chemical reaction. The ambient temperature is typically between about 10°C and about 30°C, more specifically about 25°C. The term “ambient temperature” is used interchangeably with “room temperature” herein.

[0031]

[0023] It is to be understood that although preferred aspects / embodiments and / or materials have been discussed for providing embodiments according to the present disclosure, various modifications or changes may be made without departing from the scope and spirit of this disclosure.

[0032]

[0024] In one aspect the disclosure provides 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol). 5 HAM-830230

[0033]

[0034]

[0025] A resin composition based on this as a polymercaptan-based hardener and at least one epoxy resin has good adhesion and thermomechanical properties. For example, after 1 month immersion in hot water, the resultant resin material maintains high structural adhesion properties. Resins produced using this polymercaptan-based hardener therefor have structural applications including adhesives, sealants and composites.

[0035]

[0026] In a further aspect, the disclosure provides a resin composition comprising a polymercaptan hardener which is 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane- 1, 3 -diyl)bis(oxy))bis(l -mercaptopropan -2-ol) and at least one thiol -reactive epoxy resin.

[0036]

[0027] The thiol -reactive epoxy resin reacts with the mercaptan groups of the 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol) to produce a resin. The use of this polymercaptan hardener in combination with a thiol -reactive epoxy resin significantly enhances the hot-water resistance of the resulting material keeping good adhesion and thermomechanical properties.

[0037]

[0028] In contrast to ester-based commercial polymercaptans, 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol) can create, in the presence of epoxides, networks without easy hydrolysable functional groups. Therefore, retaining its structural adhesion properties under hot-wet conditions.

[0038]

[0029] A thiol -reactive epoxy resin is any epoxy compound capable of reacting with the mercaptan groups. For example, an epoxy resin comprising functional groups selected from -OH, -COOH, -NH, -SO2, -Br, -I, -Cl, -F and combinations thereof.

[0039]

[0030] In one embodiment, the molar ratio between thiol group equivalent in the polymercaptan hardener to thiol -reactive group equivalent from epoxide ranges from about 0.25 to about 2.0, preferably from about 0.8 to about 1.2.

[0040]

[0031] Resins prepared with the molar equivalent ratio of about 0.8 to about 1.2 have particularly good properties. If the ratio of the thiol reactive groups to the thiol groups is close 6 HAM-830230

[0041] to 1 there is a minimum amount of unreacted functional groups in the final product. This improves the stability of the final product.

[0042]

[0032] In some embodiments, the composition further comprises a catalyst. The weight ratio between the catalyst and thiol -reactive epoxide may range from above about 0 to about 0.1, preferably from about 0.01 to about 0.05. The catalyst may be an amine-based catalysts, for example, l,3-Bis[3-(dimethylamino)propyl]urea (Versamid® EH 50), (2,4,6- Tris(dimethylaminomethyl)phenol) (Accelerator 960-1), and 2-(2-dimethylaminoethoxy)ethanol (JEFFCAT® ZR-70) or a phosphorus-based catalyst, for example, trioctyl phosphine.

[0043]

[0033] The use of a catalyst increases the curing rate between the polymercaptan and the epoxide.

[0044]

[0034] In some embodiments, the thiol reactive epoxy resin is selected from (i) glycidyl ethers based on aromatic alcohols, such as bisphenol F, bisphenol A (optionally brominated), bisphenol S, resorcinol, and dihydroxy-naphthalene’s, (ii) glycidyl ethers of saturated or unsaturated, branched or unbranched, cyclic or open-chain aliphatic alcohols, such as ethylene glycol, butanediol, hexanediol, cyclohexanedimethanol, and neopentylglycol; (iii) glycidyl esters of carboxylic acids such as phthalic acid, tetrahydrophthalic acid, and hexahydrophthalic acid and dimeric fatty acid; and (iv) combinations thereof.

[0045]

[0035] In one aspect the disclosure provides a method for preparing 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol) comprising:

[0046] i) reacting epichlorohydrin with 1,1,1 -tris(hydroxymethyl)ethane to produce 2,2'- (((2-methyl-2-((oxiran-2-ylmethoxy)methyl)propane-l,3- diyl)bis(oxy))bis(methylene))bis(oxirane);

[0047] ii) Opening all epoxide functions from the 2,2'-(((2-methyl-2-((oxiran-2- ylmethoxy)methyl)propane-l,3-diyl)bis(oxy))bis(methylene))bis(oxirane) with thioacetic acid followed by deacetyl atiati on of the intermediate, or reacting the 2,2'- (((2-methyl-2-((oxiran-2-ylmethoxy)methyl)propane-l,3- diyl)bis(oxy))bis(methylene))bis(oxirane) with H₂S.

[0048]

[0036] The reaction scheme is shown below: 7 HAM-830230

[0049] HO. H₂S HCl OH Base Base cat.

[0050] Trimethylolethane Araldite® DY-31 3,3'-((2-((2-hydro:><y-3-mercaptopropoxy)metyl)

[0051] Compound of Formula (A) O

[0052] -^SH

[0053]

[0054] S, S'-(((2-(p-<acetyBhiio -2-hydroxypropaxy)methyl)

[0055] -2-methylpropane-1,3-diyl>bis(oxy))bis(2-hydroxypfopane-3,1-diyl))

[0056] diathanethtoate

[0057]

[0037] In one aspect the disclosure provides an adhesive, sealant or composite comprising the resin composition described above and optionally further additional components.

[0058]

[0038] The further components include but are not limited to may optionally include one or more additives such as flexibilizers, anti-oxidants, dyes, pigments, surfactants, defoamers, silane coupling agents, dispersing agents, thixotropic agents, processing aids, flow modifiers, cure accelerators, strength enhancers, toughening agents, UV protectors (especially UV blocking dyes appropriate to enable Automatic-Optical Inspection (AOI) of Circuitry), flame retardants and the like, as well as mixtures of any two or more thereof.

[0059]

[0039] In some embodiments, the filler may be an inorganic or organic material which may be natural or synthetic.

[0060]

[0040] Flexibilizers (also called plasticizers) contemplated for use in certain embodiments of the present disclosure include compounds that reduce the brittleness of the formulation, such as, for example, branched polyalkanes or polysiloxanes that lower the glass transition temperature of the compositions. Such plasticizers include, for example, polyethers, polyesters, polythiols, polysulfides, polybutadienes such as those sold under the Poly BD® and RICON® brand names. Plasticizers, when employed, are typically present in the range of about 0.5% by weight up to about 30% by weight of the resin composition.

[0061]

[0041] Anti-oxidants contemplated for use in the practice of the present disclosure include hindered phenols (e.g., BHT (butylated hydroxytoluene), BHA (butylated hydroxyanisole), TBHQ (tertiary -butyl hydroquinone), 2,2'-methylenebis(6-tertiarybutyl-p-cresol), and the like), 8 HAM-830230

[0062] hindered amines (e.g., diphenylamine, N, N'-bis(l,4-dimethylpentyl-p-phenylene diamine, N-(4-anilinophenyl)methacrylamide, 4,4'-bis(a,a-dimethylbenzyl)diphenylamine, and the like), phosphites, and the like. When used, the quantity of anti-oxidant typically falls in the range of about 100 up to 2000 ppm, relative to the weight of the resin composition.

[0063]

[0042] Dyes contemplated for use in certain embodiments of the present disclosure include nigrosine, Orasol blue GN, phthalocyanines, fluorescent dyes (e.g., Fluoral green gold dye, and the like), and the like. When used, organic dyes in relatively low amounts (i.e., amounts less than about 0.2% by weight) provide contrast.

[0064]

[0043] Pigments contemplated for use in certain embodiments of the present disclosure include any particulate material added solely for the purpose of imparting color to the formulation, e.g., carbon black, metal oxides (e.g., Fe₂O₃, titanium oxide), and the like. When present, pigments are typically present in the range of about 0.5% by weight up to about 5% by weight, relative to the weight of the resin composition.

[0065]

[0044] Toughening agents contemplated for use in the practice of the disclosure are materials which impart enhanced impact resistance to various articles. Exemplary toughening agents include synthetic rubber containing compounds such as Hypro, Hypox, and the like.

[0066]

[0045] UV protectors contemplated for use in certain embodiments of the present disclosure include compounds which absorb incident ultraviolet (UV) radiation, thereby reducing the negative effects of such exposure on the resin or polymer system to which the protector has been added. Exemplary UV protectors include bis(l,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, silicon, powdered metallic compounds, hindered amines (known in the art as “HALS”), and the like.

[0067]

[0046] Defoamers contemplated for use in certain embodiments of the present disclosure include materials which inhibit formation of foam or bubbles when a liquid solution is agitated or sheared during processing. Exemplary defoamers contemplated for use herein include n-butyl alcohol, silicon-containing anti-foam agents, and the like.

[0068] Examples

[0069]

[0047] The detailed description of the present disclosure can be illustrated in the following examples. All chemicals were supplied by Huntsman except for:

[0070] Methanesulfonic acid, triethylamine, thioacetic acid, trimethylolpropane trimercaptopropionate and Pentaerythritol tetramercaptopropionate which were supplied by Sigma- Aldrich / Merck 9 HAM-830230

[0071] Synthesis procedure of 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol)

[0072]

[0048] Thioacetic acid (61.8 mL, 0.87 mol, 1.1 eq.) was charged in a three-neck round bottom flask. The flask was purged with nitrogen and placed in an oil bath pre-heated to 50°C. Araldite®DY-31 (100 g, 0.79 mol of epoxy functional group, 1.0 eq.) was added dropwise to thioacetic acid, keeping the internal temperature between 40-80°C. After complete addition, the mixture was stirred for a further 4 h under the same condition.

[0073]

[0049] The resultant mixture was heated to 65°C and a solution of methanesulfonic acid (15.2 g, 0.16 mol, 0.2 eq.) in ethanol (55.0 ml) was added over 15 min. After a reaction time of 6 h at 65°C, the mixture was cooled down to room temperature. Then, water (50.0 g) was added and the mixture was adjusted to pH=3 using a 25 wt% aqueous solution of NaOH. The organic layer was separated, washed twice with brine (2 x 50 ml), filtered, and concentrated under reduced pressure to obtain the desired product as a yellow viscous oil.

[0074]

[0050] The obtained product was identified from its1H-NMR spectrum.

[0075]

[0051] The structures of Araldite GY®250, Gabepro® GPM-800, Versamid®EH 50 are provided below: 10 HAM-830230

[0076] Araldite®GY-250 Versamid®EH 50

[0077] 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)

[0078] -2-methylpropane-1,3-diyl)bis(oxy)) bis(1-mercaptopropan-2-ol)

[0079]

[0080] T rimethylolpropane trimercaptopropionate Pentaerythritol tetramercaptopropionate Example 1

[0081]

[0052] The effect of different polymercaptan hardeners when cured with epoxy resins on adhesion, thermomechanical properties and hot water resistance was investigated.

[0082]

[0053] Araldite GY®250, an unmodified epoxy resin based on bisphenol A, was cured stoichiometrically with 3,3’-((2-(( 2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol). 94 pbw of 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol) (synthesized), 100 pbw of Araldite®GY-250 and 2 pbw of Versamid®EH 50 (tertiary amine accelerator) were mixed and cured at 40°C for 16h to yield a plate with about 2 mm thickness.

[0083]

[0054] Adhesion was evaluated by a lap shear strength test on aluminium at 25°C. Resin was prepared as described above and the resulting formulation was applied on Alu L165 plates previously sandblasted and degreased. Specimens were bonded by contact pressure and cured at 40°C for 16 h. Lap shear strength tests were performed at 25°C.

[0084]

[0055] For hot water immersion test, specimens were prepared following the same procedure and were immersed in water at 90°C for 1 month. After 1 month, lap shear strength tests were performed at 25°C. 11 HAM-830230

[0085]

[0056] Tensile properties were determined using the procedure set out in ISO 527-2.

[0086]

[0057] G’ onset (Tg, glass transition temperature) and tan delta were determined using the procedure set out in ISO 6721. The Tg is the temperature at which the amorphous domains of a polymer take on the characteristic properties of the glass state-brittleness, stiffness, and rigidity. The term further means the temperature at which cured resins undergo a change from a glassy state to a softer more rubbery state.

[0087]

[0058] Results are shown below in Table 1.

[0088] Comparative Example 1

[0089]

[0059] 173 pbw of Gabepro® GPM-800 (a mercaptan hardener), 100 pbw of Araldite®GY-250 and 2 pbw of Versamid®EH 50 were mixed and cured at 40°C for 16h to yield a plate with about 2 mm thickness.

[0090]

[0060] A resin was prepared as described above and the resulting formulation was applied on Alu LI 65 plates previously sandblasted and degreased. Specimens were bonded by contact pressure and cured at 40°C for 16 h. Lap shear strength tests were performed at 25°C.

[0091]

[0061] For hot water immersion test, specimens were prepared following the same procedure and were immerged in water at 90°C for 1 month. After 1 month, lap shear strength tests were performed at 25°C.

[0092]

[0062] Tensile properties were determined using the procedure set out in ISO 527-2.

[0093]

[0063] G’ onset (Tg, glass transition temperature) and tan delta were determined using the procedure set out in ISO6721.

[0094]

[0064] The results are shown below in Table 1.

[0095] Comparative Example 2

[0096]

[0065] 71 pbw of trimethylolpropane trimercaptopropionate, 100 pbw of Araldite®GY-250 and 2 pbw of Versamid®EH 50 were mixed and cured at 40°C for 16h to yield a plate with about 2 mm thickness.

[0097]

[0066] A resin was prepared as described above and the resulting formulation was applied on Alu LI 65 plates previously sandblasted and degreased. Specimens were bonded by contact pressure and cured at 40°C for 16 h. Lap shear strength tests were performed at 25°C.

[0098]

[0067] For hot water immersion test, specimens were prepared following the same procedure and were immerged in water at 90°C for 1 month. After 1 month, lap shear strength tests were performed at 25°C.

[0099]

[0068] Tensile properties were determined using the procedure set out in ISO 527-2. 12 HAM-830230

[0100]

[0069] G’ onset (Tg, glass transition temperature) and tan delta were determined using the procedure set out in ISO6721.

[0101]

[0070] The results are shown below in Table 1.

[0102] Comparative Example 3

[0103]

[0071] 68 pbw of Pentaerythritol tetramercaptopropionate, 100 pbw of Araldite®GY-250 (Huntsman) and 2 pbw of Versamid®EH 50 (Huntsman) were mixed and cured at 40°C for 16h to yield a plate with about 2 mm thickness.

[0104]

[0072] A resin was prepared as described above and the resulting formulation was applied on Alu LI 65 plates previously sandblasted and degreased. Specimens were bonded by contact pressure and cured at 40°C for 16 h. Lap shear strength tests were performed at 25°C.

[0105]

[0073] For hot water immersion test, specimens were prepared following the same procedure and were immerged in water at 90°C for 1 month. After 1 month, lap shear strength tests were performed at 25°C.

[0106]

[0074] Tensile properties were determined using the procedure set out in ISO 527-2.

[0107]

[0075] G’ onset (Tg, glass transition temperature) and tan delta were determined using the procedure set out in ISO6721.

[0108]

[0076] The results are shown below in Table 1. 13 HAM-830230

[0109] Ex.l (pbw) Comp. Ex.l (pbw) Comp. Ex.2 (pbw) Comp. Ex.3 (pbw) 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2- methylpropane- 1,3 -diyl)bis(oxy))bis( 1 - 94

[0110] mercaptopropan-2-ol)

[0111] Component Gabepro® GPM-800 173

[0112] TMPMP (trimethylolpropane trimercaptopropionate) 71

[0113] PETMP (Pentaerythritol tetramercaptopropionate) 68 Araldite®GY-250 100 100 100 100 Versamid®EH 50 2 2 2 2

[0114] G’ onset / tan delta (°C) DMA 34 / 42 -10 / 5 33 / 41 40 / 54

[0115] E modulus (MPa) 2107 + / - 41 3.0+ / - 0.2 2390+ / - 21.8 2388 + / -9.4 Maximum tensile strength (MPa) 29.2 + / - 1.9 1.5+ / - 0.1 49.0+ / - 0.7 48.1+ / - 0.5 Property Elongation at break (%) 74 + / - 10 43.4+ / - 2.8 15.6+ / - 6.7 6.1+ / - 2.4

[0116] Lap Shear Strength at 25°C (Alu L165) (MPa) 14.4+ / - 1.3 11.7+ / - 0.4 20.4+ / - 0.5 12.3 + / - 1.2 Lap Shear strength at 25 °C after 1 month immersion in

[0117] 4.0 + / - 0.7 0.3 + / - 0.1 0.0 0.0

[0118] water at 90°C (MPa)

[0119]

[0120] Table 1: Summary of the results of Example 1 and Comparative Examples 1 to 3. 14 HAM-830230

[0121] Summary

[0122]

[0077] Under normal conditions, it was found that all tested materials exhibit good to excellent adhesion and thermomechanical properties. However, after hot water immersion, it was found that only the inventive example keeps high structural adhesion performance.

Claims

15 HAM-830230ClaimsWhat is claimed is:

1. A compound, 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol).

2. A resin composition comprising a polymercaptan hardener which is 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane-l,3-diyl)bis(oxy))bis(l-mercaptopropan-2-ol), and at least one epoxy resin.

3. The resin composition according to claim 2, wherein the molar ratio of all thiol groups of the polymercaptan hardener to the epoxide groups of the epoxy resin ranges from 0.25 to 2.0, preferably from 0.8 to 1.2.

4. The resin composition according to claim 2 or claim 3, wherein the composition further comprises a catalyst.

5. The resin composition according to claim 4, wherein the weight ratio between the catalyst and epoxy resin ranges from 0 to 0.1, preferably from 0.01 to 0.05.

6. The resin composition according to claim 4 or claim 5, wherein the catalyst is an amine-based catalysts, preferably l,3-Bis[3-(dimethylamino)propyl]urea (Versamid®EH 50) or a phosphorus based catalyst, preferably trioctyl phosphine.

7. The resin composition according to any one of claims 3 to 6, wherein the epoxy resin is selected from (i) glycidyl ethers based on aromatic alcohols, such as bisphenol F, bisphenol A (optionally brominated), bisphenol S, resorcinol, and dihydroxy-naphthalene’s, (ii) glycidyl ethers of saturated or unsaturated, branched or unbranched, cyclic or open-chain aliphatic alcohols, such as ethylene glycol, butanediol, hexanediol, cyclohexanedimethanol, and neopentylglycol; (iii) glycidyl esters of carboxylic acids such as phthalic acid, tetrahydrophthalic acid, and hexahydrophthalic acid and dimeric fatty acid (iv) and combinations thereof.

8. A method for preparing 3,3'-((2-((2-hydroxy-3-mercaptopropoxy)methyl)-2-methylpropane- 1, 3 -diyl)bis(oxy))bis(l -mercaptopropan -2-ol) or analogues thereof comprising:16 HAM-830230i) reacting epichlorohydrin with 1,1,1 -tris(hydroxymethyl)ethane to produce a compound of Formula (A): 2,2'-(((2-methyl-2-((oxiran-2- ylmethoxy)methyl)propane-l,3-diyl)bis(oxy))bis(methylene))bis(oxirane); ii) Opening all epoxide functions from the compound of Formula (A) with thioacetic acid to produce a compound B, followed by deacetylation of the resultant compound B, oriii) Reacting the compound of Formula (A) with H2S.

9. An adhesive, coating, sealant or composite comprising the resin composition of any one of claims 3 to 7, and optionally further additional components.

10. The adhesive, coating, sealant or composite of claim 9, wherein the further additional components are selected from a toughener, a flexibilizer, a filler, a colorant, an NIR absorbing dye, a UV absorber, an adhesion promotor, a flame retardant and combinations thereof.

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