Polymers, processes, compositions and uses

A heat-curable powder coating composition comprising a binder in an amount of at least 1 and at most 100 pph of the composition, wherein the binder comprises:

• a) at least 10 and at most 99 pph of the binder of a polymer having:
• (a1) an acid value (AV) measured titrimetrically according to ISO 2114 of at least 105 and at most 180 mg KOH/g,
• (a2) a glass transition temperature (Tg) measured via Differential Scanning Calorimetry, of at least 30 and at most 140° C., and
• (a3) a number average molecular weight (Mn) measured via Gel Permeation Chromatography (GPC) of at least 2.1×103 Da, and wherein
• the polymer comprises one or more units selected from the group consisting of S1, S2, and combinations thereof, wherein each of S1 and S2 is represented by the following corresponding formula:
• wherein
• (i) k is an integer equal to or higher than 0, and
• (ii) m is an integer equal to or higher than 0, and
• (iii) the sum of k and m is equal to or higher than 1, and
• (iv) X is selected from the group consisting of L4, L6, L7, L8, L9, L10, L11, L12, L13, L18, L19, L20, L23, L24, L25, L26, L27, L28, L29, L30, and L31 as each of L4 to L31 is defined below, and wherein the black bold dots shown in the formulae of any one of L4 to L31 represent the attachment points of each of L4 to L31 to the S 1, and wherein the attachment points are carbon atoms,
• (v) Y is selected from the group consisting of L4, L6, L7, L8, L9, L10, L11, L12, L13, L18, L19, L20, L23, L24, L25, L26, L27, L28, L29, L30, and L31 as each of L4 to L31 is defined below, and wherein the black bold dots shown in the formulae of any one of L4 to L31 represent the attachment points of each of L4 to L31 to the S2, and wherein the attachment points are carbon atoms,
• wherein
• R1″, R2″ is independently selected from the group consisting of H and CH3,
• R3″, is a CH2 or C2-C34 optionally-substituted-hydrocarbylene,
• R4″ R5″ R6″ R7″ is independently selected from the group consisting of H, CH3, and C2-C34 optionally-substituted-hydrocarbyl,
• R8″, R9″ is independently selected from C1-C34 optionally-substituted-hydrocarbyl,
• R10″, R11″ is independently selected from C1-C12 saturated-hydrocarbyl, and
• R12″ is C4-C34 unsaturated-acyclic-hydrocarbyl,
• b) at least 10 and at most 99 pph of the binder of an acid-functional copolymerizable polymer A which is an acid-functional polyester B different from the polymer and wherein polymer A has a hydroxyl value lower than 14 and an acid value (AV) of at least 15 and at most 100 mg KOH/g, and
• c) a copolymerizable agent able to react with the polymer and the acid-functional copolymerizable polymer A, in an amount of at least 2 and at most 15 pph of the binder, wherein the copolymerizable agent is a compound which comprises at least two β-hydroxyalkylamide groups (BHA compound), and wherein
• a difference between the AV of the polymer and the AV of the copolymerizable polymer A (DeltaAV) is at least 30 mg KOH/g where each AV is measured titrimetrically according to ISO 2114, and wherein the AV of the copolymerizable polymer A is lower than the AV of the polymer,
• wherein the polymer has a MRQ of at least 1 and at most 3.8, wherein the MRQ is determined via NMR spectroscopy and is defined as:
• MRQ
• =
• s
• total
• s
• s
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• ific
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• s
• rest
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• and wherein
• Stotal=Sspecific+Srest,
• Sspecific=(total moles S1)+(total moles S2), and
• Srest=the total moles of all the units of the polymer wherein said units are not any one of S1 or S2.