Heat-curable gel coat resin composition

Abstract

A thermally curable gel coat resin composition (X) comprising an oligomeric ethylenically unsaturated resin (UR) and at least one reactive diluent (RD) wherein the oligomeric ethylenically unsaturated resin (UR) comprises at least one polyether-functional urethane (meth) acrylate (A), the polyether-functional urethane (meth) acrylate (A) can be obtained by the reaction of a mixture comprising (a) a polyfunctional isocyanate (I), (b) a hydroxyalkyl (meth) acrylate (HAA) and / or an unbranched C2-C4 polyalkylene glycol (meth) acrylate (AGA); wherein the reactive diluent (RD) comprises a monomer (B) having at least one (meth) acrylate group, and wherein the at least one polyether-functional urethane (meth) acrylate (A) comprises at least one unbranched moiety of Formula 1: wherein x is an integer from 2 to 4, n is an integer from 2 to 90.

Description

Technical Field

[0001] This invention generally relates to a thermosetting gelcoat resin composition, a coating composition comprising the thermosetting gelcoat resin composition, and the use of the thermosetting gelcoat resin composition for obtaining a non-stick cured coating layer. The invention also relates to a method for obtaining a non-stick cured coating layer, and a manufactured article having a non-stick cured coating layer on its surface. Furthermore, the invention relates to a cured gelcoat prepared by curing a coating composition comprising the thermosetting gelcoat resin composition. Background Technology

[0002] Lightweight composite materials are commonly used in the manufacture of many articles, particularly those containing fiber-reinforced composite substrates. To achieve a desirable surface appearance, a coating composition, often referred to as "gel coat," is applied to the fiber-containing supporting substrate. Parts can be manufactured with a finish having any desired color initially carried by the coating composition. In this field, thermosetting coating compositions and radiation-curing coating compositions (radiation-curing compositions) are distinct.

[0003] WO2020 / 260608 describes a radiation-curable gelcoat composition for fiber-reinforced substrates, comprising a gelcoat resin and a diluent monomer, wherein the gelcoat resin comprises a urethane (meth)acrylate prepared from polycaprolactone polyol or [(poly)carbonate-(poly)caprolactone] polyol.

[0004] Radiation-curable compositions are not practical for many types of applications. This is, for example, because additional equipment is required for radiation curing.

[0005] WO2010 / 073003 provides a gel coat comprising an unsaturated urethane resin containing acrylate and allyl ether functional groups; however, the gel coat is diluted with styrene and styrene-based compounds.

[0006] Since the commercialization of this heat-curable resin, styrene has become the primary reactive diluent due to its low cost, availability, ease of use, and consequently excellent mechanical properties. However, in recent years, government regulations have restricted styrene emissions from open molding facilities due to their harmful environmental and health effects. Therefore, the use of styrene should be avoided. Several compositions with co-alternative reactive diluents have been described in the prior art; however, low-volatility acrylate and methacrylate monomers are not suitable as substitutes for styrene because atmospheric oxygen severely hinders polymerization, resulting in an under-cured, "sticky" surface.

[0007] Purpose of the invention

[0008] Therefore, one object of the present invention is to provide a thermosetting gelcoat resin composition that at least partially overcomes the aforementioned disadvantages. Further, one object of the present invention is to provide a thermosetting gelcoat resin composition that is non-sticky after curing at high temperature or room temperature. Another object of the present invention is to provide a thermosetting gelcoat resin composition that provides good abrasion resistance after curing. Furthermore, the composition provides low volatility and low odor. Another object of the present invention is to provide a cured coating layer that retains color and high gloss when exposed to outdoor environments. These objects are achieved at least in part by the thermosetting gelcoat resin composition according to claim 1. Invention Overview

[0010] A first aspect of the present invention relates to a thermosetting gel coat resin composition (X) comprising an oligomeric olefinic unsaturated resin (UR) and at least one reactive diluent (RD).

[0011] The oligomeric olefin unsaturated resin (UR) mentioned above comprises at least one polyether-functional urethane (meth)acrylate (A), which can be obtained by reacting a mixture containing the following substances:

[0012] (a) Polyfunctional isocyanates (I);

[0013] (b) Hydroxyalkyl (meth)acrylates (HAA) and / or unbranched C2-C4 polyalkylene glycol (meth)acrylates (AGA);

[0014] (c) Optionally, a polyol with a weight-average molecular weight of 200-4000 g / mol, wherein said polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP); and

[0015] (d) Optionally, a polyol (PO) different from (c);

[0016] The reactive diluent (RD) comprises a monomer (B) having at least one (meth)acrylate group.

[0017] The at least one polyether-functional urethane (meth)acrylate (A) comprises at least one unbranched portion of Formula 1:

[0018]

[0019] Where x is an integer of 2-4, preferably 2-3, and n is an integer of 2-90, preferably 2-50, most preferably 3-30, wherein the unbranched portion of at least one formula 1 is derived from (b) and / or (c), and wherein after adding 0.003-0.01 phr of cobalt metal in the form of a carboxylate and 1.0 phr of methyl isobutyl ketone peroxide to the thermosetting gel coat resin composition (X) and applying a 500 µm layer of the composition, the composition is non-sticky after curing at 100°C for 25 minutes or less, preferably less than 15 minutes, most preferably less than 10 minutes.

[0020] Surprisingly, this thermosetting gelcoat resin composition exhibits excellent room temperature and high temperature drying properties due to the presence of urethane (meth)acrylates comprising unbranched polyalkylene glycol moieties. This allows for short standby times, meaning that if the composition is used as a gelcoat in the manufacture of fiber-reinforced articles, there is only a brief delay between gelcoat application and subsequent lamination steps. Furthermore, the thermosetting gelcoat resin composition of the present invention is found to provide short times to reach peak temperature, low volatility at low dynamic viscosity, and low odor. Cured coatings containing the thermosetting gelcoat resin composition of the present invention exhibit good abrasion resistance and good color and gloss stability when exposed to outdoor environments. Quantitative methods for drying properties, standby time, time to reach peak temperature, dynamic viscosity, odor, and abrasion resistance are provided in the experimental section.

[0021] What is particularly surprising is that a combination of the above-mentioned effects can be obtained, and these effects can be achieved with resins that are essentially free of styrene or styrene derivatives.

[0022] In a second aspect, the present invention also relates to a coating composition (Z) comprising the thermosetting gel coat resin composition (X) described in any embodiment of the first aspect.

[0023] In a third aspect, the present invention relates to a method for obtaining a non-sticky, cured coating layer, comprising the following steps:

[0024] i. Adding a free radical initiator (RI) selected from the following: peroxides, azo compounds, and mixtures thereof to the coating composition (Z) of any embodiment of the second aspect;

[0025] ii. Apply the coating composition of step (i) to a substrate to form a wet film; and

[0026] iii. Optionally, a temperature of 40-140°C, preferably 60-130°C, most preferably 80-120°C, is applied for up to 240 minutes, preferably up to 120 minutes, and more preferably up to 60 minutes.

[0027] In a fourth aspect, the invention also relates to the use of a thermosetting gel coat resin composition (X) of any embodiment of the first aspect, after the addition of a free radical initiator (RI) selected from the following: peroxides, azo compounds, and mixtures thereof, for obtaining a non-sticky cured coating layer.

[0028] In a fifth aspect, the present invention relates to a manufactured article having a surface comprising a non-adhesive curable coating layer, which is prepared by curing a coating composition (Z) of any embodiment of the second aspect by a method of one embodiment of the third aspect.

[0029] In a sixth aspect, the present invention relates to a cured gel coat prepared by curing a coating composition (Z) according to any embodiment of the second aspect, wherein the cured gel coat has a layer thickness of 100-2,000 µm, more preferably 200-1,000 µm, and most preferably 250-750 µm. Invention Details

[0031] A first aspect of the present invention relates to a thermosetting gel coat resin composition (X) comprising an oligomeric olefinic unsaturated resin (UR) and at least one reactive diluent (RD).

[0032] The oligomeric olefin unsaturated resin (UR) mentioned above comprises at least one polyether-functional urethane (meth)acrylate (A), which can be obtained by reaction of a mixture containing the following substances:

[0033] (a) Polyfunctional isocyanates (I);

[0034] (b) Hydroxyalkyl (meth)acrylates (HAA) and / or unbranched C2-C4 polyalkylene glycol (meth)acrylates (AGA);

[0035] (c) Optionally, a polyol with a weight-average molecular weight of 200-4000 g / mol, wherein said polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP); and

[0036] (d) Optionally, a polyol (PO) different from (c); wherein the reactive diluent (RD) comprises a monomer (B) having at least one (meth)acrylate group.

[0037] The at least one polyether-functional urethane (meth)acrylate (A) comprises at least one unbranched portion of Formula 1:

[0038]

[0039] Where x is an integer of 2-4, preferably 2-3, and n is an integer of 2-90, preferably 2-50, and most preferably 3-30, wherein the unbranched portion of at least one formula 1 is derived from (b) and / or (c), and

[0040] Wherein, after adding 0.003-0.01 phr of cobalt metal in the form of carboxylate and 1.0 phr of methyl isobutyl ketone peroxide to the thermosetting gel coat resin composition (X) and applying a 500 µm layer of the composition, the composition is non-sticky after curing at 100°C for 25 minutes or less, preferably less than 15 minutes, and most preferably less than 10 minutes.

[0041] The weight-average molecular weight of polyether polyols (PEPs) is determined by the hydroxyl value (OHV, unit: mg KOH / g, ASTM E222). For example, for difunctional polyethers, the weight-average molecular weight = (1000 × 56.1 × 2) / OHV.

[0042] If (b) is hydroxyalkyl (meth)acrylate (HAA), then the reaction mixture contains an unbranched C2-C4 polyalkylene glycol polyether polyol (PEP) to obtain an oligomeric olefin unsaturated resin (UR). If (b) is an unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA), then the reaction mixture may or may not contain an unbranched C2-C4 polyalkylene glycol polyether polyol (PEP) to obtain an oligomeric olefin unsaturated resin (UR).

[0043] Preferably, the at least one polyether-functional urethane (meth)acrylate (A) can be obtained by reacting a mixture comprising:

[0044] (a) 10-50 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a multifunctional isocyanate (I);

[0045] (b) 5-40 wt%, more preferably 8-35 wt%, most preferably 10-30 wt% of hydroxyalkyl (meth)acrylate (HAA) and / or 40-90 wt%, more preferably 45-85 wt%, most preferably 50-80 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA);

[0046] (c) Optionally, 25-80 wt%, more preferably 30-75 wt%, most preferably 35-70 wt% of a polyol with a weight average molecular weight of 200-4000 g / mol, wherein said polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP); and

[0047] (d) Optionally, a polyol (PO) different from (c);

[0048] The sum of I, AGA, HAA, (optional) PEP, and (optional) PO is 100%.

[0049] More preferably, the at least one polyether-functional urethane (meth)acrylate (A) can be obtained by reacting a mixture comprising:

[0050] (a) Polyfunctional isocyanates (I);

[0051] (b) Unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA);

[0052] (c) Optionally, a polyol with a weight average molecular weight of 200-4000 g / mol, wherein the polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP).

[0053] (d) Optionally, a polyol (PO) different from (c);

[0054] Alternatively, it can be obtained through a reaction involving a mixture of the following substances:

[0055] (a) Polyfunctional isocyanates (I);

[0056] (b) Hydroxyalkyl (meth)acrylates (HAA) and / or unbranched C2-C4 polyalkylene glycol (meth)acrylates (AGA);

[0057] (c) A polyol with a weight-average molecular weight of 200-4000 g / mol, preferably 500-2000 g / mol, more preferably 500-1500 g / mol, wherein the polyol is an unbranched C2-C4 polyalkylene glycol polyether polyol (PEP), and the amount used is such that the molar ratio of the isocyanate groups contained in the multifunctional isocyanate (I) to the total molar ratio of the isocyanate groups contained in the polyether polyol (PEP) and the hydroxyl groups contained in the polyol (PO) is 1.8-2.5, more preferably 1.9-2.2; and

[0058] (d) Optionally, a polyol (PO) different from (c).

[0059] Most preferably, the at least one polyether-functional urethane (meth)acrylate (A) can be obtained by reacting a mixture comprising:

[0060] (a) 10-50 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a multifunctional isocyanate (I);

[0061] (b) 40-90 wt%, more preferably 45-85 wt%, most preferably 50-80 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA), and optionally hydroxyalkyl (meth)acrylate (HAA);

[0062] (c) Optionally, a polyol with a weight average molecular weight of 200-4000 g / mol, wherein the polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP).

[0063] (d) Optionally, a polyol (PO) different from (c);

[0064] The sum of I, AGA, (optional) HAA, (optional) PEP, and (optional) PO is 100 wt%;

[0065] Alternatively, it can be obtained through a reaction involving a mixture of the following substances:

[0066] (a) 10-45 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a multifunctional isocyanate (I);

[0067] (b) 5-40 wt%, more preferably 8-35 wt%, most preferably 10-30 wt% of hydroxyalkyl (meth)acrylate (HAA) and / or 5-75 wt%, more preferably 10-70 wt%, most preferably 15-65 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA);

[0068] (c) A polyol with a weight-average molecular weight of 200-4000 g / mol, preferably 500-2000 g / mol, more preferably 500-1500 g / mol, wherein the polyol is an unbranched C2-C4 polyalkylene glycol polyether polyol (PEP), and the amount used is such that the molar ratio of the isocyanate groups contained in the multifunctional isocyanate (I) to the total molar ratio of the isocyanate groups contained in the polyether polyol (PEP) and the hydroxyl groups contained in the polyol (PO) is 1.8-2.5, more preferably 1.9-2.2; and

[0069] (d) Optionally, a polyol (PO) different from (c);

[0070] The sum of I, AGA, HAA, PEP and (optional) PO is 100 wt%.

[0071] In this invention, the thermosetting gelcoat resin composition refers to a resin composition that is cured or cured (thus forming a film with good cohesion and mechanical resistance, good scratch resistance, and low haze) by free radical copolymerization induced by free radical initiators (which generate free radicals upon exposure to heat). The good cohesion and mechanical resistance of the cured gelcoat film prevent damage to the film during demolding. Good scratch resistance helps maintain the good appearance of the gelcoat film throughout the service life of the manufactured article containing the film. High transparency and low haze values ​​are particularly advantageous if the gelcoat film does not contain pigments or fillers.

[0072] When used in this specification to name compounds, the prefix "(meth)acryl" includes both "acryl" and "methacryl", referring to compounds containing at least one CH2=CHCOO- group or CH2=CCH3COO- group, mixtures thereof, and mixtures of such compounds.

[0073] Carbamate (meth)acrylates are well-known and commercially available products in this field.

[0074] In this invention, urethane (meth)acrylate means a compound containing at least one urethane group corresponding to Formula 2 and at least one (meth)acrylate group corresponding to Formula 3, wherein R is a hydrogen atom or a methyl group.

[0075]

[0076] In this invention, polyether-functional urethane (meth)acrylate (A) means an urethane (meth)acrylate comprising at least one unbranched portion of Formula 1.

[0077]

[0078] Preferably, the (reaction) mixture for obtaining the polyether-functional urethane (meth)acrylate (A) comprises:

[0079] (a) 10-45 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a multifunctional isocyanate (I);

[0080] (b-1) 5-40 wt%, more preferably 8-35 wt%, most preferably 10-30 wt% of hydroxyalkyl (meth)acrylate (HAA);

[0081] (c) 25-80 wt%, more preferably 30-75 wt%, most preferably 35-70 wt% of a polyol with a weight-average molecular weight of 200-4000 g / mol, more preferably 500-2000 g / mol, more preferably 500-1500 g / mol, wherein the polyol is an unbranched C2-C4 polyalkylene glycol polyether polyol (PEP); and

[0082] (d) Optionally, 1-35 wt%, more preferably 1-30 wt%, most preferably 1-25 wt% of a polyol (PO) different from (c);

[0083] The sum of I, HAA, PEP, and (optional) PO is 100%.

[0084] Alternatively, if an additional unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) is present, the (reaction) mixture for obtaining the polyether-functional urethane (meth)acrylate (A) preferably comprises:

[0085] (a) 10-45 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a multifunctional isocyanate (I);

[0086] (b-1) 2-40 wt%, more preferably 5-35 wt%, most preferably 7-30 wt% of hydroxyalkyl (meth)acrylate (HAA);

[0087] (b-2) 5-75 wt%, more preferably 10-70 wt%, and most preferably 15-65 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA);

[0088] (c) 10-70 wt%, more preferably 15-55 wt%, most preferably 20-50 wt% of a polyol with a weight-average molecular weight of 200-4000 g / mol, more preferably 500-2000 g / mol, and more preferably 500-1500 g / mol, wherein the polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP); and

[0089] (d) Optionally, 1-35 wt%, more preferably 1-30 wt%, most preferably 1-25 wt% of a polyol (PO) different from (c);

[0090] The sum of I, HAA, AGA, PEP, and (optional) PO is 100%.

[0091] Alternatively, the (reaction) mixture for obtaining the polyether-functional urethane (meth)acrylate (A) preferably comprises:

[0092] (a) 10-45 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a polyfunctional isocyanate (I);

[0093] (b-2) 15-80 wt%, more preferably 20-75 wt%, most preferably 25-70 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA);

[0094] (c) 10-75 wt%, more preferably 15-70 wt%, most preferably 20-65 wt% of a polyol with a weight average molecular weight of 200-4000 g / mol, more preferably 500-2000 g / mol, and more preferably 500-1500 g / mol, wherein the polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP); and

[0095] (d) Optionally, 1-35 wt%, more preferably 1-30 wt%, most preferably 1-25 wt% of a polyol (PO) different from (c);

[0096] The sum of I, AGA, PEP, and (optional) PO is 100%.

[0097] More preferably, the (reaction) mixture for obtaining the polyether-functional urethane (meth)acrylate (A) comprises:

[0098] (a) 10-50 wt%, more preferably 12-40 wt%, most preferably 15-35 wt% of a multifunctional isocyanate (I); and

[0099] (b-2) 40-90 wt%, more preferably 45-85 wt%, and most preferably 50-80 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA);

[0100] The sum of I and AGA is 100%.

[0101] Alternatively, if an additional hydroxyalkyl (meth)acrylate (HAA) is present, the (reaction) mixture for obtaining the polyether-functional urethane (meth)acrylate (A) preferably comprises:

[0102] (a) 10-50 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a multifunctional isocyanate (I);

[0103] (b-1) 5-55 wt%, more preferably 8-50 wt%, most preferably 10-45 wt% of hydroxyalkyl (meth)acrylate (HAA);

[0104] (b-2) 20-75 wt%, more preferably 25-70 wt%, and most preferably 30-65 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA);

[0105] The sum of I, HAA, and AGA is 100%.

[0106] Alternatively, the (reaction) mixture for obtaining the polyether-functional urethane (meth)acrylate (A) preferably comprises:

[0107] (a) 10-45 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a polyfunctional isocyanate (I);

[0108] (b-2) 5-75 wt%, more preferably 10-70 wt%, most preferably 15-65 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA); and

[0109] (d) 10-70 wt%, more preferably 15-55 wt%, and most preferably 20-50 wt% of a polyol (PO) different from polyether polyol (PEP);

[0110] The sum of I, AGA, and PO is 100%.

[0111] The multifunctional isocyanate (I) is preferably selected from aromatic, aliphatic, or mixed aliphatic-aromatic isocyanates. The multifunctional isocyanate (I) contains at least two, preferably two, isocyanate groups per molecule. More preferably, the multifunctional isocyanate (I) is selected from trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), propylene diisocyanate, ethyl ethylene diisocyanate, 2,3-dimethyl ethylene diisocyanate, 1-methyltrimethylene diisocyanate, cyclopentyl-1,3-diisocyanate, cyclohexyl-1,4-diisocyanate, cyclohexyl-1,2-diisocyanate, phenyl-1,3-diisocyanate, phenyl-1,4-diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, biphenyl-4,4'-diisocyanate, and bis(4-isocyanatophenyl)methane (MDI). Naphthalene-1,5-diisocyanate, naphthalene-1,4-diisocyanate, 1-isocyanatomethyl-5-isocyanato-1,3,3-trimethylcyclohexane (isophorone diisocyanate, IPDI), bis(4-isocyanatocyclohexyl)methane (H12-MDI), 4,4'-diisocyanatodiphenyl ether, 2,3-bis(8-isocyanatooctyl)-4-octyl-5-hexylcyclohexene, trimethylhexamethylene diisocyanate, 1,3-bis(2-isocyanatopropyl-2-yl)benzene, m-tetramethylxylenylidene diisocyanate (TMXDI), urea diketone of the above diisocyanates, isocyanurate of the above diisocyanates, ureocarboxylate of the above diisocyanates, and mixtures thereof.

[0112] If a polyfunctional isocyanate (I) with more than two isocyanate groups per molecule is used, branched urethane (meth)acrylates will be formed.

[0113] Most preferably, the multifunctional isocyanate (I) is selected from aliphatic isocyanates, and most preferably from hexamethylene diisocyanate (HDI) and its urea diketone, isocyanurate or urea carbamate, bis(4-isocyanatocyclohexyl)methane (H12-MDI), 1-isocyanatomethyl-5-isocyanato-1,3,3-trimethylcyclohexane (isophorone diisocyanate, IPDI), and mixtures thereof.

[0114] Multifunctional isocyanates (I) can be obtained from petrochemical feedstocks.

[0115] Alternatively and preferably, where possible, the multifunctional isocyanate (I) is derived from renewable feedstocks. Particularly preferred is isophorone diisocyanate (1-isocyanatomethyl-5-isocyanato-1,3,3-trimethylcyclohexane (IPDI)) derived from bio-based acetone. Other preferred polyfunctional isocyanates (I) derived from renewable raw materials include, for example, 1,5-pentamethylene diisocyanate, diisocyanate of methyl or ethyl esters of L-lysine, isosorbide diisocyanate, furanyl diisocyanate, bis(4-isocyanato-2-methoxyphenoxy)alkane, bis(4-isocyanato-2,6-dimethoxyphenoxy)alkane, 2,4-diisocyanato-1-pentadecanylbenzene, diisocyanates and polyisocyanates based on fatty acids, dimer fatty acids and vegetable oils, 1-isocyanato-10-[(isocyanatomethyl)thio]decane, and products known under the trade name TOLONATE™ X FLO 100.

[0116] In another alternative, multifunctional isocyanates (I) are derived from petrochemical feedstocks and / or renewable feedstocks.

[0117] In the context of this specification, "renewable raw material" means a natural resource that will be replenished through natural regeneration or other cyclical processes (within a finite timescale on a human timescale) to replace the portion that has been used and consumed. The total amount of a substance or mixture of substances obtained from such a renewable raw material should have a bio-based carbon content of at least 20 wt% of the total carbon content of the substance or mixture, determined using ASTM D6866-20 standard.

[0118] Hydroxyalkyl (meth)acrylates (HAAs) are generally hydroxy-functionalized (meth)acrylates, more specifically '(meth)acryloyl monohydroxy' compounds, where '(meth)acryloyl monohydroxy' means a compound containing one hydroxyl group and one or more (meth)acryloyl groups. Acrylates are particularly preferred. Typically, hydroxyalkyl (meth)acrylates (HAAs) differ from unbranched C2-C4 polyalkylene glycol (meth)acrylates (AGAs).

[0119] Suitable examples of hydroxyalkyl (meth)acrylates (HAAs) include, but are not limited to, hydroxyethyl (meth)acrylates, hydroxypropyl (meth)acrylates, hydroxybutyl (meth)acrylates, polyoxypropylene mono(meth)acrylates, or any of those hydroxylated monomers that are further reacted with lactones or lactides (which are added to these hydroxyl groups via a ring-opening reaction).

[0120] Equally suitable hydroxyalkyl (meth)acrylates (HAAs) are esterification products of aliphatic and / or aromatic polyols with (meth)acrylic acid, having a residual average hydroxyl functionality of about 1. Preferred are partially esterification products of (meth)acrylic acid with tri-, tetra-, penta-, or hexa-alliphatic polyols or mixtures thereof. Reaction products of such polyols with propylene oxide, or reaction products of such polyols with lactones or lactides added to these polyols via ring-opening reactions, can also be used until the desired residual hydroxyl functionality is achieved. Those skilled in the art know that the esterification of polyols with (meth)acrylic acid yields a mixture of (meth)acrylate components, and a simple and suitable method for characterizing this mixture is by measuring its hydroxyl value (mg KOH / g). Suitable compounds (HAAs) are, for example, (meth)acrylates of straight-chain and branched polyols, wherein at least one hydroxyl functional group remains free. Suitable examples include, but are not limited to, glyceryl diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, bis(trimethylolpropane) triacrylate, bis(pentaerythritol) pentaacrylate, and (poly)propoxylated equivalents.

[0121] Most preferably, the hydroxyalkyl (meth)acrylate (HAA) is selected from 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, and mixtures thereof.

[0122] Unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) preferably relates to the following general formula (Formula 4):

[0123]

[0124] Where R 1 It is hydrogen or methyl, R 2 It is a straight-chain or branched C2-C6 aliphatic group, where x is an integer of 2-4, preferably 2-3, y is an integer of 0-2, m is an integer of 0-12, p is an integer of 0-12, preferably 0-10, more preferably 0-8, and n is an integer of 2-12, preferably 2-10, more preferably 2-8.

[0125] Examples of suitable unbranched C2-C4 polyalkylene glycol (meth)acrylates (AGA) include poly(ethoxylated) derivatives of hydroxyalkyl (meth)acrylates, trimethylolpropane di(meth)acrylate, glyceryl di(meth)acrylate, pentaerythritol tri(meth)acrylate, or mixtures thereof.

[0126] Unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) is more preferably alkoxylated (meth)acrylate having the following general formula (Formula 5):

[0127]

[0128] Where R 1 It is hydrogen or methyl, x is an integer of 2-4, preferably 2-3, and n is an integer of 2-12, preferably 2-10, more preferably 2-8. Most preferably, the unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) is a polyethylene glycol mono(meth)acrylate containing 2-12 ethylene oxide (EO) units.

[0129] The amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) is calculated by dividing the total number of moles of (meth)acrylated unsaturated groups contained in hydroxyalkyl (meth)acrylate (HAA) and unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) by the total weight of the polyether-functional urethane (meth)acrylate (A), and is expressed as milliequivalents (meq / g) of the degree of unsaturation of the polyether-functional urethane (meth)acrylate (A). The amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) is preferably at least 1.0 meq / g, more preferably at least 1.1 meq / g, even more preferably 1.0-2.0 meq / g, and most preferably 1.1-1.9 meq / g.

[0130] The amounts of (meth)acrylated and olefinically unsaturated groups can also be measured by nuclear magnetic resonance spectroscopy and expressed as meq / g solid material. The composition sample is dissolved in a deuterated solvent (e.g., DMSO-d6). The sample is then quantified. 1 ¹H-NMR analysis was performed using 1,3,5-bromobenzene as an internal standard to measure the molar concentrations of (meth)acrylated and olefinically unsaturated groups. Comparison of the signals from the aromatic protons of the internal standard with those attributed to the (meth)acrylated and olefinically unsaturated double bonds allowed for the calculation of the molar concentrations of (meth)acrylated and olefinically unsaturated groups using the formula (A×B) / C, where A is the integral of the ¹H signal of the double bond in the sample, B is the number of moles of the internal standard, and C is the integral of the aromatic ¹H signal of 1,3,5-bromobenzene.

[0131] Alternatively, the amount of (meth)acrylate esterification and the amount of olefinic unsaturated groups can also be measured by titration, following the aza-Michael addition reaction of morpholine to the unsaturated groups (N-methylpyrrolidone as solvent, excess morpholine reacts with acetic anhydride). The tertiary amine formed is titrated continuously with HCl. The results need to be corrected for the measured basicity of the sample (blank material, meq / g solids). Results are also expressed in meq / g solids.

[0132] The polyether polyol (PEP) of unbranched C2-C4 polyalkylene glycol is preferably a poly(oxyalkylene) glycol containing unbranched alkyl groups having 2-4 carbon atoms; more preferably, the polyether polyol (PEP) of unbranched C2-C4 polyalkylene glycol is selected from poly(oxyethylene) glycol, poly(oxypropylene) glycol, poly(oxytetramethylene) glycol, and mixtures thereof.

[0133] Unbranched C2-C4 polyalkylene glycol polyether polyols (PEPs) include products obtained by polymerization of cyclic oxides (e.g., ethylene oxide, propylene oxide, or tetrahydrofuran), or by addition of one or more such oxides to a multifunctional initiator (e.g., water, ethylene glycol, propylene glycol, diethylene glycol, cyclohexanediol, glycerol, trimethylolpropane, pentaerythritol, or bisphenol A). Particularly useful polyethers include polyoxyethylene glycol and triols, poly(ethylene oxide-propylene oxide) glycols and triols obtained by simultaneous or sequential addition of ethylene oxide and propylene oxide to a suitable initiator, and polytetramethylene glycol obtained by polymerization of tetrahydrofuran. Amine-terminated polyether polyols may also be used.

[0134] Most preferably, the unbranched C2-C4 polyalkylene glycol polyether polyol (PEP) is selected from poly(oxyethylene) glycol, 1,3-polypropylene glycol, poly(oxytetramethylene) glycol, and mixtures thereof.

[0135] The weight-average molecular weight of the unbranched C2-C4 polyalkylene glycol polyether polyol (PEP) is preferably 200-4000 g / mol, more preferably 500-2000 g / mol, even more preferably 500-2000 g / mol, and most preferably 500-1500 g / mol.

[0136] Alternatively and preferably, where possible, the unbranched C2-C4 polyalkylene glycol polyether polyol (PEP) is a poly(oxyalkylene) glycol derived from renewable raw materials, more preferably a poly(oxyalkylene) glycol derived from bio-based 1,3-propanediol.

[0137] In another alternative, unbranched C2-C4 polyalkylene glycol polyether polyols (PEPs) are derived from petrochemical feedstocks and / or renewable feedstocks.

[0138] Preferably, the unbranched portion of Formula 1 obtained from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and / or polyether polyol (PEP) is 5-70% by weight, more preferably 10-60%, based on the total weight of the thermosetting gelcoat resin composition (X).

[0139] In another preferred embodiment, the unbranched portion of Formula 1 is derived from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA), and the unbranched portion of Formula 1 is 5-70% by weight, more preferably 10-60%, based on the total weight of the thermosetting gelcoat resin composition (X).

[0140] In a further preferred embodiment, the unbranched portion of Formula 1 is derived from polyether polyol (PEP), and the wt% of the unbranched portion of Formula 1 is 5-70%, more preferably 10-60%, based on the total weight of the thermosetting gelcoat resin composition (X).

[0141] In another preferred embodiment, the unbranched portion of Formula 1 is derived from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and polyether polyol (PEP), and the wt% of the unbranched portion of Formula 1 is 5-80%, more preferably 7-70%, and most preferably 10-60%, based on the total weight of the thermosetting gelcoat resin composition (X).

[0142] Preferably, the polyol (PO) is selected from monomeric polyols, polymeric polyols, or mixtures thereof. On average, each molecule of polyol (PO) has two or more hydroxyl groups, preferably two to four, and more preferably two.

[0143] Preferably, the monomeric polyol is a diol. The diol is preferably selected from 1,2-ethylene glycol, 1,2- and 1,3-propanediol, diethylene glycol, triethylene glycol, 1,2- and 1,4-butanediol, 2,2'-oxobis(ethylene-1-ol), 2,2-dimethyl-1,3-propanediol, 2-methyl-2,4-pentanediol, 1,4-bis(hydroxymethyl)cyclohexane, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,18-octadecanediol, 1,21-eicosodecanediol, 1,25-eicosodecanediol, isosorbide, isomannitol, isoadurenol, and mixtures thereof.

[0144] The polymeric polyol is preferably selected from polyester polyols, polycarbonate polyols, branched C2-C4 polyalkylene glycols containing branched alkyl groups, and mixtures thereof. The weight-average molecular weight of the polymeric polyol is preferably 200-4000 g / mol.

[0145] Suitable polyester polyols have at least two hydroxyl groups, more preferably two hydroxyl groups, and are prepared by stoichiometric excess of one or more diols and one or more diacids.

[0146] - The diol is preferably selected from 1,2-ethylene glycol, 1,2- and 1,3-propanediol, diethylene glycol, triethylene glycol, 1,2- and 1,4-butanediol, 2,2'-oxobis(ethylene-1-ol), 2,2-dimethyl-1,3-propanediol, 2-methyl-2,4-pentanediol, 1,4-bis(hydroxymethyl)cyclohexane, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,18-octadecanediol, 1,21-eicosodecanediol, 1,25-eicosodecanediol, isosorbide, isomannitol, isoadurenol, and mixtures thereof;

[0147] - The diacid is preferably selected from malonic acid, succinic acid, glutaric acid, adipic acid, octanoic acid, and dimer fatty acids having up to forty carbon atoms, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and mixtures thereof.

[0148] Optionally, one or more hydroxycarboxylic acids (e.g., hydroxybenzoic acid, lactic acid, γ-hydroxybutyric acid, δ-hydroxyvalerate and ε-hydroxyhexanoic acid) can be combined with one or more diols to prepare polyester polyols.

[0149] Preferably, the polyester polyol is a condensation product of a diacid selected from diacid, isophthalic acid, and mixtures thereof, and a stoichiometric excess of a diol selected from 1,4-butanediol, 1,6-hexanediol, 2,2'-oxobis(ethylene-1-ol), 2,2-dimethyl-1,3-propanediol, and mixtures thereof, wherein the polyester is characterized by a hydroxyl value of 20-400 mg KOH / g, preferably 30-250 mg KOH / g, more preferably 40-150 mg KOH / g, and an acid value of less than 3 mg KOH / g, preferably less than 2 mg KOH / g, more preferably less than 1 mg KOH / g, wherein the acid value is residual and generated by unreacted terminal acid functional groups.

[0150] Alternatively and preferably, where possible, the diol (e.g., 1,3-propanediol), diacid (e.g., succinic acid), or hydroxycarboxylic acid (e.g., lactic acid) used to prepare the polyester polyol is derived from renewable raw materials.

[0151] In another alternative, polyester polyols are derived from petrochemical feedstocks and / or renewable feedstocks.

[0152] In this invention, polyester polyols having two hydroxyl groups should be understood as polyesters having almost two hydroxyl groups and negligible carboxylic acid groups, because it is difficult to achieve 100% conversion.

[0153] Suitable polycarbonate polyols are compounds having at least two hydroxyl groups and are prepared by reacting polyols (e.g., 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, 1,4-bis(hydroxymethyl)cyclohexane, 2,2-bis(4-hydroxycyclohexyl)propane, neopentyl glycol, trimethylolpropane, or pentaerythritol) with dicarbonates (e.g., dimethyl carbonate, diethyl carbonate, or diphenyl carbonate) or phosgene.

[0154] Alternatively and preferably, where possible, the polycarbonate polyol is derived from renewable raw materials, more preferably from bio-based polyols (e.g., bio-based 1,3-propanediol or 1,5-pentanediol).

[0155] In another alternative, polycarbonate polyols are derived from petrochemical feedstocks and / or renewable feedstocks.

[0156] Suitable branched C2-C4 polyalkylene glycols are poly-1,2-propanediols having at least two hydroxyl groups, more preferably having two hydroxyl groups.

[0157] Preferably, the (reaction) mixture used to obtain the polyether-functional urethane (meth)acrylate (A) does not contain polyols (PO).

[0158] Preferably, the polyether-functional urethane (meth)acrylate (A) used in this invention comprises at least two (meth)acrylate groups, and preferably up to six, more preferably up to four (meth)acrylate groups.

[0159] The polyether-functional urethane (meth)acrylate (A) used in this invention more preferably contains two or three (meth)acrylate groups, more specifically two or three acrylate groups. Particularly suitable polyether-functional urethane (meth)acrylate (A) is selected from urethane di(meth)acrylate, and even more preferably from urethane diacrylate.

[0160] A reactive diluent (RD) is used as a solvent for the oligomeric olefinic unsaturated resin (UR) to adjust the dynamic viscosity of the thermosetting gelcoat resin composition (X). Preferably, it is applied at a temperature of 23°C and for 25 seconds, according to DIN EN ISO 3219. -1 The dynamic viscosity of the thermosetting gelcoat resin composition (X) was determined at a shear rate of 250-10,000 mPa·s, more preferably 300-5,000 mPa·s, and most preferably 400-3,000 mPa·s.

[0161] Preferably, the oligomeric olefin unsaturated resin (UR) comprises 30-90 wt%, more preferably 45-80 wt%, and the reactive diluent (RD) comprises 10-70 wt%, more preferably 20-55 wt%, based on the total weight of the thermosetting gelcoat resin composition (X). The weight ratio of the oligomeric olefin unsaturated resin (UR) to the reactive diluent (RD) is preferably 0.25-20.00, more preferably 0.40-10.00, and most preferably 0.75-4.00.

[0162] The reactive diluent (RD) comprises a monomer (B) having at least one (meth)acrylate group. Preferably, the monomer (B) having at least one (meth)acrylate group is selected from monomers (M1) having one (meth)acrylate group and monomers (M2) having at least two (meth)acrylate groups.

[0163] Suitable monomers (M1) having a (meth)acrylate group may be selected from methacrylic acid, methyl methacrylate (MMA), ethyl methacrylate, n-butyl methacrylate (BuMA), tert-butyl methacrylate (tBuMA), cyclohexyl methacrylate (CHMA), glycidyl methacrylate, isobornyl methacrylate (IBOMA), hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA), acrylic acid, methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (BuA), tert-butyl acrylate (tBuA), 2-ethylhexyl acrylate (2EHA), isooctyl acrylate (IOA), isobornyl acrylate (IBOA), isobornyl methacrylate (IBoMA), hydroxyethyl acrylate (HEA), cyclic trimethylolpropionic acid acrylate (CTFA), vinyl acetate (VoAc), benzyl methacrylate (BMA), ethylene glycol C2-C6 monoalkyl ether (meth)acrylate, propylene glycol C2-C6 monoalkyl ether (meth)acrylate, and any mixture thereof.

[0164] More preferably, the monomer (M1) having a (meth)acrylate group may be selected from methyl methacrylate (MMA), n-butyl methacrylate (BuMA), tert-butyl methacrylate (tBuMA), cyclohexyl methacrylate (CHMA), hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA), isobornyl acrylate (IBOA), isobornyl methacrylate (IBoMA), benzyl methacrylate (BMA), diethylene glycol monomethyl ether acrylate, diethylene glycol monomethyl ether methacrylate, diethylene glycol monoethyl ether acrylate, diethylene glycol monoethyl ether methacrylate, and any mixture thereof.

[0165] The monomer (M2) having at least two (meth)acrylate groups may be selected from di and tri(meth)acrylated monomers, such as 1,6-hexanediol di(meth)acrylate (HDD(M)A), di or tripropylene glycol di(meth)acrylate (DPGD(M)A, TPGD(M)A), di or triethylene glycol di(meth)acrylate (DEGD(M)A, TEGD(M)A), tetrapropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tricyclodecanediethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate and their ethoxylated and / or propoxylated derivatives. Trimethylolpropane tri(meth)acrylate (TMPT(M)A) and its ethoxylated and / or propoxylated derivatives, glycerol tri(meth)acrylate and its ethoxylated and / or propoxylated derivatives, pentaerythritol tri(meth)acrylate (PETI(M)A) and its ethoxylated and / or propoxylated derivatives, glycerol tri(meth)acrylate and its ethoxylated and / or propoxylated derivatives, diesterol di(meth)acrylate (such as isosorbide di(meth)acrylate) and its ethoxylated and / or propoxylated derivatives, bisphenol A di(meth)acrylate and its ethoxylated and / or propoxylated derivatives. Preferably, the monomer (M2) having at least two (meth)acrylate groups is selected from 1,6-hexanediol di(meth)acrylate (HDD(M)A), di- or triethylene glycol di(meth)acrylate (DEGD(M)A, TEGD(M)A), tetraethylene glycol di(meth)acrylate, and any mixture thereof.

[0166] Preferably, the reactive diluent (RD) comprises more than 25.0 wt% of a monomer (M2) having at least two (meth)acrylate groups.

[0167] The reactive diluent (RD) may include a vinyl monomer (M3). The vinyl monomer (M3) may be selected from styrene, methylstyrene, ethylstyrene, halostyrene, vinyltoluene, and mixtures thereof. The wt% of the monomer (B) having at least one (meth)acrylate group contained in the reactive diluent (RD) is preferably greater than 75 wt%, more preferably greater than 85 wt%, and most preferably greater than 95 wt%.

[0168] Most preferably, the thermosetting gelcoat resin composition (X) is substantially free of styrene, methylstyrene, ethylstyrene, halostyrene, vinyltoluene, and methyl methacrylate. In the context of this invention, "substantially free of" means containing less than 1.0 wt%, preferably less than 0.5 wt%, and most preferably less than 0.1 wt% (based on the total content referred to therein).

[0169] Preferably, the thermosetting gelcoat resin composition (X) is in the form of a homogeneous solution, rather than a non-aqueous dispersion of urethane (meth)acrylate particles, meaning that the particle size distribution cannot be measured by standard light scattering methods known to those skilled in the art. Particularly preferably, the volume-weighted particle size distribution of particles smaller than 400 nm is 0%.

[0170] Urea (meth)acrylates are well known in the art and have been described, for example, in GB-A-2217722. A method for obtaining a polyether-functional urethane (meth)acrylate (A) may include the following steps:

[0171] - Provides a multifunctional isocyanate (I), optionally in the presence of a reactive diluent (RD) that is chemically inert to isocyanates;

[0172] - Add hydroxyalkyl (meth)acrylate (HAA) and optionally unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) to it, wherein the molar ratio of the sum of isocyanate groups derived from the polyfunctional isocyanate (I) to the sum of hydroxyl groups derived from the hydroxyalkyl (meth)acrylate (HAA) and optionally unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) is 1.001-2.5;

[0173] - Add an unbranched C2-C4 polyalkylene glycol polyether polyol (PEP) and optionally a polyol (PO) different from the polyether polyol (PEP), provided that the molar ratio of the sum of the hydroxyl groups of the unbranched C2-C4 polyalkylene glycol polyether polyol (PEP) and optionally the polyol (PO) to the sum of the isocyanate groups of the polyfunctional isocyanate (I) is 0.9-1.1; and

[0174] - Optionally, add (further) reactive diluent (RD).

[0175] Another preferred method for obtaining polyether-functional urethane (meth)acrylate (A) includes the following steps:

[0176] - Provides unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA), optional hydroxyalkyl (meth)acrylate (HAA), and further optional polyol (PO) different from polyether polyol (PEP), optionally in the presence of a reactive diluent (RD) that is chemically inert to isocyanate;

[0177] - Add a polyfunctional isocyanate (I) to it, wherein the molar ratio of the sum of isocyanate groups derived from the polyfunctional isocyanate (I) to the sum of hydroxyl groups derived from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA), hydroxyalkyl (meth)acrylate (HAA), and optionally a polyol (PO) is 0.9-1.1; and

[0178] - Optionally, add (further) reactive diluent (RD).

[0179] Another preferred method for obtaining polyether-functional urethane (meth)acrylate (A) may include the following steps:

[0180] - Providing a polyether polyol (PEP) of a multifunctional isocyanate (I) and an unbranched C2-C4 polyalkylene glycol, optionally in the presence of a reactive diluent (RD) that is chemically inert to isocyanates, wherein the molar ratio of the sum of isocyanate groups derived from the multifunctional isocyanate (I) to the sum of hydroxyl groups derived from the unbranched C2-C4 polyalkylene glycol (PEP) is 1.001-2.5;

[0181] - Add unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and optionally a polyol (PO) other than polyether polyol (PEP), provided that the molar ratio of the sum of the hydroxyl groups of the polyether polyol (PEP) derived from the unbranched C2-C4 polyalkylene glycol, the unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA), and optionally the polyol (PO) to the sum of the isocyanate groups derived from the polyfunctional isocyanate (I) is 0.9-1.1; and

[0182] - Optionally, add (further) reactive diluent (RD).

[0183] Independent of the method for obtaining polyether-functionalized urethane (meth)acrylate (A), it is preferable to use a process catalyst, typically known to enhance the reactivity of the isocyanate groups and hydroxyl groups, in any step. Such process catalysts are most preferably metal catalysts, such as zinc alkoxides, bismuth alkoxides, zirconium alkoxides, or mixtures thereof. Commercial examples include Valikat® ZB8 (from Umicore), Valikat® Bi 2010 (from Umicore), or Borchers® DecaZirconium 15 (from Borchers).

[0184] The thermosetting gelcoat resin composition (X) may further comprise at least one unsaturated resin different from the polyether-functionalized urethane (meth)acrylate (A). Preferably, the oligomeric olefinic unsaturated resin (UR) included in the thermosetting gelcoat resin composition (X) comprises at least 15 wt%, preferably at least 30 wt%, more preferably at least 45 wt% (based on the total weight of the oligomeric olefinic unsaturated resin (UR)) of at least one polyether-functionalized urethane (meth)acrylate (A), and at most 85 wt%, preferably at most 70 wt%, more preferably at most 55 wt% (based on the total weight of the oligomeric olefinic unsaturated resin (UR)) of at least one unsaturated resin different from the polyether-functionalized urethane (meth)acrylate (A). The at least one unsaturated resin different from the polyether-functionalized urethane (meth)acrylate (A) may be selected from unsaturated polyester resins, vinyl ester resins, urethane (meth)acrylates, epoxy (meth)acrylates, polyester (meth)acrylates, and mixtures thereof.

[0185] A thermocurable gelcoat resin composition (X) can be cured by adding at least one free radical initiator (RI). When using a low-reactivity free radical initiator (RI) and a high curing temperature is desired, the at least one free radical initiator (RI) can be included in the thermocurable gelcoat resin composition (X). Preferably, the at least one free radical initiator (RI) is added to the thermocurable gelcoat resin composition (X) just before the composition is applied and cured. Preferably, the at least one free radical initiator (RI) included in or added to the thermocurable gelcoat resin composition (X) is 0.05-10% by weight, more preferably 0.2-4%, and most preferably 0.5-2.5%, relative to the total weight of the thermocurable gelcoat resin composition (X).

[0186] Free radical initiators (RIs) can be thermal initiators, and they are azo compounds (e.g., azobisisobutyronitrile (AIBN), 1,1'-azobis(cyclohexanenitrile), 1,1'-azobis(2,4,4-trimethylpentane)), CC unstable compounds (e.g., benzinol), peroxides, and mixtures thereof.

[0187] More preferably, the free radical initiator (RI) can be a thermal initiator, which is a peroxide. Peroxides include organic and inorganic peroxides. In one embodiment, the thermal initiator is soluble in the composition. Examples of peroxides include, for example, percarbonates (structural formula -OC(O)O-), peroxyesters (structural formula -C(O)OO-), diacid peroxides (also known as peracid anhydrides, structural formula -C(O)OOC(O)-), dialkyl peroxides or perethers (structural formula -OO-), hydroperoxides (structural formula -OOH), etc. Peroxides can also be oligomerizing or polymerizing.

[0188] Thermal initiators may include, for example, percarbonates, peresters, or peranhydrides. Examples of peranhydrides include benzoyl peroxide (BPO) and lauroyl peroxide (commercially available as Laurox™). Examples of peresters include tert-butyl perbenzoate and 2-ethylhexyl perlaurate. Examples of percarbonates include di-tert-butyl percarbonate and di-2-ethylhexyl percarbonate or monopercarbonate.

[0189] Even more preferably, the thermal initiator is an organic peroxide. Examples of organic peroxides are tert-alkyl hydroperoxides (e.g., tert-butyl hydroperoxide), other hydroperoxides (e.g., cumene hydroperoxide), ketone peroxides (perketones, which are addition products of hydrogen peroxide and ketones, such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, and acetylacetone peroxide), peroxy esters or peracids (e.g., tert-butyl perester, benzoyl peroxide, peracetate, and perbenzoate ester), lauroyl peroxide, including (ii) peroxy esters, and perethers (e.g., diethyl peroxide).

[0190] Most preferably, the free radical initiator (RI) is selected from methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cumene hydroperoxide, benzoyl peroxide, 1,1-bis(tert-butylperoxy)cyclohexane, O,O-tert-butyl-O-isopropyl monoperoxy carbonate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 2,2-di(tert-butylperoxy)butane, 1-cyano-1-(tert-butylazo)cyclohexane, and any combination thereof.

[0191] The thermocurable gelcoat resin composition (X) may further include a curing accelerator (CA), preferably selected from organometallic compounds, nitrogen-containing compounds, and mixtures thereof.

[0192] Suitable nitrogen-containing compounds may be selected from alkylanilines, and more preferably from N,N-dimethylaniline (DMA), N,N-diethylaniline (DEA), N,N-dimethyl-p-toluidine (DMpT), N,N-diisopropyl-p-toluidine (DiPpT), N,N-dihydroxyethyl-p-toluidine (DHEpT), ethoxylated dihydroxyethyl-p-toluidine, and mixtures thereof.

[0193] Suitable organometallic compounds may be selected from carboxylates of transition metals. More preferably, the metal contained in the organometallic compound is selected from cobalt, manganese, copper, and iron.

[0194] Preferably, the curing accelerator (CA) contained in the thermosetting gelcoat resin composition (X) is 0.05-10% by weight, more preferably 0.2-4% by weight, and most preferably 0.5-2.5% by weight relative to the total weight of the thermosetting gelcoat resin composition (X).

[0195] When the thermocurable gel coat resin composition (X) contains a metal-organic compound as a curing accelerator (CA), the wt% of the metal is preferably 0.0005-0.5%, more preferably 0.001-0.4%, and most preferably 0.001-0.2%, based on the total composition.

[0196] Alternatively, the thermocurable gelcoat resin composition (X) can be cured by photochemical radiation, particularly by ultraviolet radiation or an electron beam.

[0197] In some embodiments, the thermosetting gelcoat resin composition (X) may contain an inhibitor. Suitable examples of inhibitors include, but are not limited to, phenolic inhibitors, such as hydroquinone (HQ), methyl hydroquinone (THQ), 4-tert-butylcatechol (TBC), benzoquinone (BQ), tert-butylhydroquinone (TBHQ), di-tert-butylhydroquinone (DTBHQ), hydroquinone monomethyl ether (MEHQ), 2,6-di-tert-butyl-4-methylphenol (BHT), phenothiazine (PTZ), etc. When present, the inhibitor is preferably present in an amount of up to 0.5 wt%, particularly 0.0001-0.2 wt%, and preferably 0.01-0.1 wt% of the composition.

[0198] Another embodiment of the present invention provides a heat-curable gelcoat resin composition (X) that is non-sticky after curing. Preferably, after adding 0.003-0.01 phr (parts per hundred parts of resin) of cobalt metal in the form of carboxylate and 1.0 phr (parts per hundred parts of resin) of methyl isobutyl ketone peroxide to the heat-curable gelcoat resin composition (X) and applying a 500 µm layer of the composition, the composition is non-sticky after curing at 100°C for 25 minutes or less, preferably less than 15 minutes, and most preferably less than 10 minutes.

[0199] In the context of this invention, non-stickiness means that no stickiness is detected when the surface to which the composition has been applied is touched with a clean fingertip.

[0200] In the context of this invention, phr (parts per hundred parts of resin) indicates that the entity referred to is added to 100 parts by weight of a thermosetting gelcoat resin composition (X).

[0201] Preferably, the heat-curable gelcoat resin composition (X) has high transparency and low haze value after curing. Preferably, the haze value (measured on a free gelcoat film) of the heat-curable gelcoat resin composition (X) after curing is less than 5%, more preferably less than 3%, and most preferably less than 2%.

[0202] Any feature of the first aspect may be as described accordingly in any other aspect.

[0203] A second aspect of the invention relates to a coating composition (Z) comprising the thermosetting gelcoat resin composition (X).

[0204] The coating composition (Z) may additionally include one or more of the following: pigments, fillers, thixotropic agents, auxiliary drying agents, dispersants, antisettling agents, sagging control agents, light or UV stabilizers, flow modifiers, leveling agents, defoamers, wetting agents, surfactants, adhesion promoters, flame retardants, slip additives, antifouling additives, and antigraffiti additives.

[0205] The coating composition (Z) can be particularly used as a gel coat for molded articles (preferably fiber-reinforced articles), such as swimming pools, boats, wind turbine blades, window sills, and automotive body parts. Molded articles containing the gel coat can be prepared using conventional processes. For example, the gel coat composition can be spread onto the mold surface using any of a variety of conventional techniques (e.g., brushing or spraying), typically as a relatively thick layer to maximize its weather resistance and abrasion resistance, and if the molded article is fiber-reinforced, to help conceal any fiber-reinforced patterns that may be visible through the gel coat due to inherent resin shrinkage around the fibers during curing. Preferably, the cured gel coat layer thickness is 100-2,000 µm, more preferably 200-1,000 µm, and most preferably 250-750 µm. After the gel coat is applied to the surface of the mold, it is allowed to cure at least partially. The plastic (optionally fiber-reinforced plastic) is then applied to the partially or fully cured gelcoat using any of a variety of conventional techniques, and the resulting laminate containing the gelcoat and substrate is cured. Advantageously, the gelcoat is cured on the substrate at a temperature below 40°C. For some applications, particularly where a high curing rate is required, curing the gelcoat at elevated temperatures, preferably 40-140°C, more preferably 60-130°C, and most preferably 80-120°C, may be advantageous.

[0206] Any feature of the second aspect may be as described accordingly in any other aspect.

[0207] A third aspect of the present invention relates to a method for obtaining a non-sticky, cured coating layer, the method comprising the following steps:

[0208] i. Add a free radical initiator (RI) selected from the following: peroxides, azo compounds, and mixtures thereof to the coating composition (Z);

[0209] ii. Apply the coating composition of step (i) to a substrate to form a wet film; and

[0210] iii. Optionally, a temperature of 40-140°C, preferably 60-130°C, most preferably 80-120°C, is applied for up to 240 minutes, preferably up to 120 minutes, more preferably up to 60 minutes, most preferably 1.0-240 minutes, 1.0-120 minutes, or 1.0-60 minutes.

[0211] If step iii is not used, a non-sticky cured coating layer can be obtained by curing at room temperature.

[0212] Any feature of the third aspect may be as described accordingly in any other aspect.

[0213] The fourth aspect of the invention relates to the use of a thermosetting gel coat resin composition (X) after the addition of a free radical initiator (RI) selected from peroxides, azo compounds, and mixtures thereof for obtaining a non-sticky cured coating layer.

[0214] Any feature of the fourth aspect may be as described in the corresponding description in any of the other aspects.

[0215] The fifth aspect of the invention relates to a manufactured article having a surface comprising a non-adhesive, curable coating layer, prepared by curing a coating composition (Z).

[0216] Any feature of the fifth aspect may be as described in the corresponding description in any other aspect.

[0217] Example

[0218] The following raw materials were used in the examples:

[0219] HEA 2-hydroxyethyl acrylate

[0220] IPDI isophorone diisocyanate

[0221] BHT 2,6-di-tert-butyl-4-methylphenol

[0222] BISOMER®PEA6 is derived from GEO Specialty Chemicals (a polyethylene glycol monoacrylate containing 6 ethylene oxide (EO) units).

[0223] Polytetramethylene glycol 650 (weight average molecular weight 650 g / mol) was obtained from BASF.

[0224] Polytetramethylene glycol 1000 (weight average molecular weight 1000 g / mol) was obtained from BASF.

[0225] Poly(1,3-propanediol) 1000 (Velvetol® H1000, weight average molecular weight 1000 g / mol) was obtained from WeylChem International.

[0226] Poly(1,2-propanediol) 1000 (VORANOL™ 1010L, weight-average molecular weight 1000 g / mol) was obtained from Dow.

[0227] Polyethylene glycol 1000 (weight average molecular weight 1000 g / mol) was obtained from Sigma-Aldrich.

[0228] Polycaprolactone diol 1250 (Capa® 2125, weight average molecular weight 1250 g / mol) was obtained from Ingevity.

[0229] EBECRYL® 117 (hydroxyl-functional monoacrylate, hydroxyl value 160 mg KOH / g) is derived from Allnex.

[0230] Tetraethylene glycol diacrylate was obtained from Sigma Aldrich.

[0231] EOEOA (diethylene glycol monoethyl ether acrylate) is derived from BASF.

[0232] Accelerator NL51-PN (solvent mixture solution containing 6% cobalt) was obtained from Nouryon.

[0233] Accelerator N553S (a solvent mixture solution containing 1.9% cobalt) was obtained from Nouryon.

[0234] CUROX® i300 (methyl isobutyl ketone peroxide, 50 wt%) is from United Initiators

[0235] HDDA hexanediol diacrylate

[0236] EBECRYL® 284 (87% bifunctional urethane acrylate, diluted with 13% HDDA) is from allnex.

[0237] EBECRYL® 4680 (80% tetrafunctional urethane acrylate, diluted with 20% HDDA) is from Allnex.

[0238] EBECRYL® 4820 (65% trifunctional urethane acrylate, diluted with 35% HDDA) is from Allnex.

[0239] Valikat® ZB8 (metal catalyst) is derived from Umicore.

[0240] Borchers® Deca Zirconium 15 (metal catalyst) from Borchers

[0241] FP 9151 is a white pigment paste based on unsaturated polyester resin, containing 60 wt% TiO2.

[0242] (EBECRYL® 284, EBECRYL® 4680 and EBECRYL® 4820 are resin compositions containing urethane acrylates that are not part of this invention.)

[0243] The following test methods were used in the examples:

[0244] - Room temperature (23°C, 50% relative humidity) drying properties: A free radical initiator (RI, e.g., CUROX® i300) was added to the resin composition in the amounts given in the table below. The time of initiator addition is taken as the start time. The sample was then applied to a glass strip with a wet film thickness of 500 µm (determined using an Elcometer wet film thickness tester). The glass strip was then placed on a drying recorder (Neurtek BK 3 drying recorder), and the film was periodically tested with a clean finger. The time when the film felt sticky but no wet gel coat adhered to the finger was recorded as the "standby time." The time when the needle of the drying recorder no longer pierced the layer and the needle mark disappeared corresponds to the "final drying time."

[0245] - High-Temperature Drying: Add the free radical initiator (RI, such as CUROX® i300) to the resin composition in the amounts given in the table below. Then apply the sample to a glass plate with a wet film thickness of 500 µm (determined using an Elcometer wet film thickness tester). Place the glass plates in a ventilated oven at 80 or 100 °C, respectively. The time the glass plate enters the oven is recorded as the starting time. Periodically test the film with a clean finger. The time when the film feels sticky but no wet gel coat adheres to the finger is recorded as the "standby time". Continue testing with your finger until the film no longer feels sticky to the touch; this time is recorded as the "non-stick time".

[0246] - Pour 20g of the dryness test sample into a 25mm diameter glass tube fitted with a thermocouple and monitor the time between the addition of the free radical initiator (RI) and the recorded peak temperature ("time to peak temperature").

[0247] - The dynamic viscosity of the coating composition was measured at a constant shear rate using a cone-plate rheometer MCR100 (Paar-Physica) at 251 l / s and 23 °C according to DIN EN ISO 3219.

[0248] - Abrasion Resistance: After the standby time, the gelcoat is backed with a fiber-reinforced polyester laminate. Two layers of glass fiber mat (30 g / m²) saturated with pre-promoted laminating resin VIAPAL® VUP 4714BET / 52 (from Allnex) are then spread by hand. 2The resin was applied to the back of the gelcoat. It was cured with 2 phr of Curox i300 initiator at 80°C for 5 minutes. After curing, the laminated gelcoat was removed from the glass substrate. The abrasion resistance of the gelcoat layer was tested using a Taber® 5750 linear abrasion tester. Commercial gelcoat samples were tested as a reference. The gelcoat was subjected to 25 cycles of abrasive wear using different abrasives (CS-8: mild abrasion, CS-10: moderate abrasion, CS-19: severe abrasion), followed by a visual evaluation of the coating layer. The stroke speed was 25 cycles / minute, and the stroke length was 25 mm. The total weight was 350 g or 500 g (as shown in the table below).

[0249] - Odor: The odor of the resin composition was assessed by placing it 10 cm away from the nose: "O" indicates no odor detected, "△" indicates a slight odor, and "S" indicates a strong odor.

[0250] - NCO content, acid value, and hydroxyl value were measured according to methods well known in the art.

[0251] - The NCO / OH ratio of the reaction mixture is determined as the molar ratio of the isocyanate groups contained in the polyfunctional isocyanate (I) to the sum of the hydroxyl groups contained in the polyether polyol (PEP) and (if present) polyol (PO).

[0252] - The amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) is calculated by dividing the total number of moles of (meth)acrylated unsaturated groups contained in the hydroxyalkyl (meth)acrylate (HAA) and the unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) by the total weight of the polyether-functional urethane (meth)acrylate (A).

[0253] - Haze value of the free film: The film applied in the "High Temperature Drying" test was used. After cooling, the free, cured gel coat layer was removed from the glass plate, and the transparency was tested on the free film using a haze meter (BYK Gardner XL-211 Hazegard Hazemeter). The average haze value was calculated based on measurements from four different points on the free film.

[0254] Example 1

[0255] 142.3 g of IPDI, 0.11 g of BHT, and 0.26 g of Valikat® ZB8 were placed in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 45°C. Then, 74.3 g of HEA was added over 60 minutes, maintaining the exothermic reaction below 70°C. The reaction was continued at 60°C until the NCO content was 12.4%. Then, 310.1 g of poly(1,3-propanediol) 1000 was added over 30 minutes. After the addition was complete, the reaction mixture was maintained at 70°C until the residual NCO content was below 0.2%, and then the reaction was terminated. The NCO / OH ratio of the reaction mixture was 2.12. The calculated amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) was 1.22 meq / g.

[0256] Example 2

[0257] 142.3 g of IPDI, 0.11 g of BHT, and 0.26 g of Valikat® ZB8 were placed in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 45°C. Then, 74.3 g of HEA was added over 60 minutes, maintaining the exothermic reaction below 70°C. The reaction was continued at 60°C until the NCO content was 12.4%. Then, 303.2 g of polytetramethylene glycol 1000 was added over 30 minutes. After the addition was complete, the reaction mixture was maintained at 70°C until the residual NCO content was below 0.2%, and then the reaction was terminated. The NCO / OH ratio of the reaction mixture was 2.12. The calculated amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) was 1.23 meq / g.

[0258] Example 3

[0259] 142.3 g of IPDI, 0.11 g of BHT, and 0.26 g of Valikat® ZB8 were placed in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 45°C. Then, 74.3 g of HEA was added over 60 minutes, maintaining the exothermic reaction below 70°C. The reaction was continued at 60°C until the NCO content was 12.4%. Then, 303.2 g of polyethylene glycol 1000 was added over 30 minutes. After the addition was complete, the reaction mixture was maintained at 70°C until the residual NCO content was below 0.2%, and then the reaction was terminated. The NCO / OH ratio of the reaction mixture was 2.14. The calculated amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) was 1.23 meq / g.

[0260] Example 4

[0261] 2318.4 g of BISOMER® PEA6, 0.31 g of BHT, and 0.293 g of Valikat® ZB8 were placed in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 45°C. Then, 766.9 g of IPDI was added over 30 minutes, maintaining the exothermic reaction below 70°C. After the addition was complete, the reaction mixture was maintained at 70°C until the residual NCO content was below 0.2%, at which point the reaction was terminated. The calculated amount of (meth)acrylated unsaturated groups in the polyether-functional urethane (meth)acrylate (A) was 1.24 meq / g.

[0262] Example 5

[0263] 483 g of IPDI and 717 g of polytetramethylene glycol 650 were placed together in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 55 °C, and 0.68 g of Borchers® Deca Zirconium 15 was added to the mixture. After the exothermic reaction was complete, the reaction was continued at 70 °C until the NCO content was 7.6%. Subsequently, 0.58 g of Valikat® ZB8 was added to the reactor, followed by 717.1 g of BISOMER® PEA6 over 120 minutes via the feeding funnel. After the addition was complete, the reaction mixture was maintained at 70 °C until the residual NCO content was below 0.2%, and then the reaction was terminated. The NCO / OH ratio of the reaction mixture was 1.98. The calculated amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) was 1.11 meq / g.

[0264] Example 6

[0265] 500.03 g of IPDI, 763.9 g of polytetramethylene glycol 650, and 0.75 g of BHT were placed in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 45°C, and 0.75 g of Valikat® ZB8 was added. The reaction was continued at 60°C until the NCO content was 7.7%. Then, 261.6 g of HEA was added over 60 minutes to maintain the exothermic reaction below 70°C. After the addition was complete, the reaction mixture was maintained at 70°C until the residual NCO content was below 0.2%, and then the reaction was terminated. The NCO / OH ratio of the reaction mixture was 1.93. The calculated amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) was 1.48 meq / g.

[0266] Comparative Example 1

[0267] 142.3 g of IPDI, 0.1 g of BHT, and 0.26 g of Valikat® ZB8 were placed in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 45°C. Then, 74.3 g of HEA was added over 60 minutes, maintaining the exothermic reaction below 70°C. The reaction was continued at 60°C until the NCO content was 12.4%. Then, 307.3 g of poly(1,2-propanediol) 1000 was added over 30 minutes. After the addition was complete, the reaction mixture was maintained at 70°C until the residual NCO content was below 0.2%, then the reaction was terminated.

[0268] Comparative Example 2

[0269] 112.5 g of IPDI, 0.1 g of BHT, and 0.24 g of Valikat® ZB8 were placed in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 45°C. Then, 58.8 g of HEA was added over 60 minutes, maintaining the exothermic reaction below 70°C. The reaction was continued at 60°C until the NCO content was 12.4%. Then, 309.8 g of polycaprolactone diol 1250 was added over 30 minutes. After the addition was complete, the reaction mixture was maintained at 70°C until the residual NCO content was below 0.2%, and then the reaction was terminated.

[0270] Comparative Example 3

[0271] 152.8 g of EBECRYL® 117, 0.1 g of BHT, and 0.06 g of Valikat® ZB8 were placed in a reaction flask equipped with a stirrer, a liquid feeding funnel, and a thermometer. The reaction mixture was heated to 45°C. Then, 48.2 g of IPDI was added over 60 minutes, maintaining the exothermic reaction below 70°C. After the addition was complete, the reaction mixture was maintained at 70°C until the residual NCO content was below 0.2%, at which point the reaction was terminated.

[0272] Comparative Example 4

[0273] In a 3-liter reactor equipped with a stirrer and a distillation column, 298.3 g of 2-methyl-1,3-propanediol, 190.6 g of isophthalic acid, 169.9 g of phthalic anhydride, 70.6 g of maleic anhydride, 0.22 g of toluene-hydroquinone, and 0.3 g of tin catalyst were charged. The mixture was heated to 160 °C under atmospheric pressure and a nitrogen flow. When the partial acid value was in the same range as the total acid value, the mixture was heated to 220 °C. When water was no longer being distilled off, a vacuum was applied. The reaction mixture was heated until the acid value was below 10 mg KOH / g. The reaction mixture was then cooled to 90 °C, and 1306 g of tetraethylene glycol diacrylate was added with stirring until a homogeneous and clear product was obtained.

[0274] Preparation and testing results of the coating composition

[0275] Add the raw materials in the order of the rows in the table. Then test these coating compositions as described above. Compositions 1-19 refer to the coating compositions of the present invention, and comparative compositions 1-12 refer to the comparative compositions not of the present invention. The test results shown in Table 1 clearly show that these coating compositions exhibit good room temperature drying properties. Conversely, the test results shown in Table 2 indicate that the comparative coating compositions (not of the present invention) cannot dry within 24 hours at room temperature.

[0276] Table 1

[0277]

[0278] The unbranched portion of Formula 1 obtained from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and / or polyether polyol (PEP) is expressed in wt%, based on the total weight of the thermosetting gelcoat resin composition.

[0279] Table 2

[0280]

[0281] The unbranched portion of Formula 1 obtained from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and / or polyether polyol (PEP) is expressed in wt%, based on the total weight of the thermosetting gelcoat resin composition.

[0282] The test results shown in Tables 3 and 4 clearly demonstrate that coating compositions 10-16 exhibit good high-temperature drying properties, while comparative coating compositions 7-10 (not of this invention) cannot even dry within 60 minutes at 100°C. Comparative coating composition 11 shows acceptable high-temperature drying properties; however, due to its high styrene content, this coating composition has a strong odor.

[0283] Table 3

[0284]

[0285] The unbranched portion of Formula 1 obtained from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and / or polyether polyol (PEP) is expressed in wt%, based on the total weight of the thermosetting gelcoat resin composition.

[0286] Table 4

[0287]

[0288] The unbranched portion of Formula 1 obtained from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and / or polyether polyol (PEP) is expressed in wt%, based on the total weight of the thermosetting gelcoat resin composition.

[0289] 100% solids content unsaturated polyester, based on 3-methyl-1,5-pentanediol, isophthalic acid, phthalic acid, and maleic anhydride, with a hydroxyl value of 50 mg KOH / g and an acid value of 10 mg KOH / g.

[0290] As can be clearly seen from the test results shown in Table 5, coating compositions 17-19 exhibit good high-temperature drying properties, while the comparative coating composition 12 (not of this invention) cannot even dry within 60 minutes at 100°C.

[0291] Table 5

[0292]

[0293] The unbranched portion of Formula 1 obtained from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and / or polyether polyol (PEP) is expressed in wt%, based on the total weight of the thermosetting gelcoat resin composition. Light stabilizer (from BASF).

[0294] As can be clearly seen from the test results shown in Table 6, coating compositions 2-4 exhibit better abrasion resistance than commercial gelcoat samples.

[0295] Table 6

[0296]

[0297] No visible damage (best) Minor scratches Numerous scratches

[0298] Matte finish (worst)

[0299] Table 7

[0300]

[0301] The unbranched portion of Formula 1 obtained from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and / or polyether polyol (PEP) is expressed in wt%, based on the total weight of the thermosetting gelcoat resin composition.

Claims

1. A thermosetting gelcoat resin composition (X) comprising an oligomeric olefinic unsaturated resin (UR) and at least one reactive diluent (RD), The oligomeric olefin unsaturated resin (UR) comprises at least one polyether-functional urethane (meth)acrylate (A) that can be obtained by reacting a mixture containing the following substances: (a) Polyfunctional isocyanates (I); (b) Hydroxyalkyl (meth)acrylates (HAA) and / or unbranched C2-C4 polyalkylene glycol (meth)acrylates (AGA); (c) Optionally, a polyol with a weight-average molecular weight of 200-4000 g / mol, wherein said polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP); and (d) Optionally, a polyol (PO) different from (c); The reactive diluent (RD) comprises a monomer (B) having at least one (meth)acrylate group, and The at least one polyether-functional urethane (meth)acrylate (A) comprises at least one unbranched portion of Formula 1: Where x is an integer of 2-4, preferably 2-3, and n is an integer of 2-90, preferably 2-50, and most preferably 3-30, wherein the unbranched portion of at least one formula 1 is derived from (b) and / or (c), and Wherein, after adding 0.003-0.01 phr of cobalt metal in the form of carboxylate and 1.0 phr of methyl isobutyl ketone peroxide to the thermosetting gel coat resin composition (X) and applying a 500 µm layer of the composition, the composition is non-sticky after curing at 100°C for 25 minutes or less, preferably less than 15 minutes, and most preferably less than 10 minutes.

2. The thermosetting gelcoat resin composition (X) according to claim 1, wherein the at least one polyether-functional urethane (meth)acrylate (A) is obtained by reacting a mixture comprising: (a) Polyfunctional isocyanates (I); (b) Unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and optional hydroxyalkyl (meth)acrylate (HAA); (c) Optionally, a polyol with a weight average molecular weight of 200-4000 g / mol, wherein the polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP). (d) Optionally, a polyol (PO) different from (c); Alternatively, it can be obtained through a reaction involving a mixture of the following substances: (a) Polyfunctional isocyanates (I); (b) Hydroxyalkyl (meth)acrylates (HAA) and / or unbranched C2-C4 polyalkylene glycol (meth)acrylates (AGA); (c) A polyol with a weight-average molecular weight of 200-4000 g / mol, wherein the polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP); the amount of the polyol is such that the molar ratio of the isocyanate groups contained in the polyfunctional isocyanate (I) to the total molar ratio of the isocyanate groups contained in the polyether polyol (PEP) and the hydroxyl groups contained in the polyol (PO) is 1.8-2.5; and (d) Optionally, a polyol (PO) different from (c).

3. The thermosetting gelcoat resin composition (X) according to claim 1 or 2, wherein the mixture comprises: (a) 10-45 wt%, more preferably 12-40 wt%, and most preferably 15-35 wt% of a polyfunctional isocyanate (I); (b-1) 5-40 wt%, more preferably 8-35 wt%, most preferably 10-30 wt% of hydroxyalkyl (meth)acrylate (HAA); (c) 25-80 wt%, more preferably 30-75 wt%, most preferably 35-70 wt% of a polyol with a weight average molecular weight of 200-4000 g / mol, wherein the polyol is a non-branched C2-C4 polyalkylene glycol polyether polyol (PEP); and (d) Optionally, 1-35 wt%, more preferably 1-30 wt%, most preferably 1-25 wt% of a polyol (PO) different from (c); The sum of I, HAA, PEP and (optional) PO is 100 wt%.

4. The thermosetting gelcoat resin composition (X) according to claim 1 or 2, wherein the mixture comprises: (a) 10-50 wt%, more preferably 12-40 wt%, most preferably 15-35 wt% of a multifunctional isocyanate (I); and (b-2) 40-90 wt%, more preferably 45-85 wt%, and most preferably 50-80 wt% of unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA); The sum of I and AGA is 100wt%.

5. The thermosetting gelcoat resin composition (X) according to any one of claims 1-4, wherein the amount of (meth)acrylated unsaturated groups contained in the polyether-functional urethane (meth)acrylate (A) is at least 1.0 meq / g.

6. The thermosetting gelcoat resin composition (X) according to any one of claims 1-5, wherein the wt% of the oligomeric olefinic unsaturated resin (UR) is 30-90 wt%, preferably 45-80 wt%, and wherein the weight percentage of the reactive diluent (RD) is 10-70 wt%, preferably 20-55 wt%, based on the total weight of the thermosetting gelcoat resin composition (X); wherein the sum of UR and RD is 100%.

7. The thermosetting gel coat resin composition (X) according to any one of claims 1-6, wherein the weight ratio of oligomeric olefinic unsaturated resin (UR) to reactive diluent (RD) is 0.25-20.00, preferably 0.40-10.00, and most preferably 0.75-4.

00.

8. The thermosetting gel coat resin composition (X) according to any one of claims 1-7, wherein the monomer (B) having at least one (meth)acrylate group contained in the reactive diluent (RD) has a weight percentage greater than 75 wt%, preferably greater than 85 wt%, and most preferably greater than 95 wt%.

9. The thermosetting gelcoat resin composition (X) according to any one of claims 1-8, wherein the reactive diluent (RD) comprises more than 25.0 wt% of a monomer (M2) having at least two (meth)acrylate groups.

10. The thermosetting gelcoat resin composition (X) according to any one of claims 1-9, wherein, based on the total weight of the oligomeric olefin unsaturated resin (UR), the oligomeric olefin unsaturated resin (UR) comprises at least 15 wt%, preferably at least 30 wt%, more preferably at least 45 wt% of at least one polyether-functional urethane (meth)acrylate (A) and at most 85 wt%, preferably at most 70 wt%, more preferably at most 55 wt% of at least one unsaturated resin different from the polyether-functional urethane (meth)acrylate (A), said unsaturated resin preferably selected from unsaturated polyester resins, vinyl ester resins, urethane (meth)acrylates, epoxy (meth)acrylates, polyester (meth)acrylates, and mixtures thereof.

11. The thermosetting gelcoat resin composition (X) according to any one of claims 1-10, wherein the unbranched portion of formula 1 obtained from unbranched C2-C4 polyalkylene glycol (meth)acrylate (AGA) and / or polyether polyol (PEP) is 5-70 wt%, more preferably 10-60 wt%, based on the total weight of the thermosetting gelcoat resin composition (X).

12. The thermosetting gelcoat resin composition (X) according to any one of claims 1-11, wherein the composition further comprises a curing accelerator (CA), preferably selected from organometallic compounds, nitrogen-containing compounds, and mixtures thereof.

13. The thermosetting gel coat resin composition (X) according to claim 12, wherein a metal-organic compound is present, and wherein the metal contained in the metal-organic compound is preferably selected from cobalt, manganese, copper and iron.

14. The thermosetting gelcoat resin composition (X) according to claim 13, wherein the metal weight percentage is 0.0005-0.5 wt%, based on the total composition.

15. The thermosetting gel coat resin composition (X) according to any one of claims 1-14, wherein the composition is substantially free of styrene, methylstyrene, ethylstyrene, halostyrene, vinyltoluene and methyl methacrylate.

16. A coating composition (Z) comprising the thermosetting gelcoat resin composition (X) according to any one of claims 1-15.

17. The coating composition (Z) according to claim 16, wherein the coating composition (Z) further comprises one or more of pigments, fillers, thixotropic agents, auxiliary drying agents, dispersants, antisettling agents, sagging control agents, light or UV stabilizers, flow modifiers, leveling agents, defoamers, wetting agents, surfactants, adhesion promoters, flame retardants, slip additives, antifouling additives, and antigraffiti additives.

18. A cured gel coat prepared by curing the coating composition (Z) according to any one of claims 16-17, said cured gel coat having a layer thickness of 100-2,000 µm, more preferably 200-1,000 µm, and most preferably 250-750 µm.

19. A method for obtaining a non-sticky, cured coating layer, comprising the following steps: i. Adding a free radical initiator (RI) selected from the following: peroxides, azo compounds, and mixtures thereof to the coating composition (Z) according to any one of claims 16-17; ii. Apply the coating composition from step (i) onto a substrate to form a wet film, and iii. Optionally, a temperature of 40-140°C, preferably 60-130°C, most preferably 80-120°C, is applied for up to 240 minutes, preferably up to 120 minutes, and more preferably up to 60 minutes.

20. Use of the thermosetting gelcoat resin composition (X) of any one of claims 1-15, after the addition of a free radical initiator (RI) selected from the following: peroxides, azo compounds, and mixtures thereof, to obtain a non-sticky cured coating layer.

21. A manufactured article having a surface comprising a non-adhesive, curable coating layer, prepared by curing the coating composition (Z) of any one of claims 16-17 by the method of claim 19.

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