FR3118051A1 - ACTINIC RADIATION CURABLE COMPOSITIONS CONTAINING A POLYAMIDE - Google Patents

Abstract

A polyamide is combined with one or more compounds curable by actinic radiation to provide compositions, particularly compositions which are liquid at room temperature or which are gels at room temperature but liquid at elevated temperatures, which can be cured by exposure to actinic radiation such as UV or visible light to provide articles with improved properties, such as higher fracture energy value, as a result of the inclusion of the polyamide. Such actinic radiation curable compositions are particularly useful as resins in additive manufacturing processes.

Description

ACTINIC RADIATION CURABLE COMPOSITIONS CONTAINING A POLYAMIDE

Field of invention

The invention relates to polyamide-containing compositions capable of being cured by actinic radiation to provide useful articles, including three-dimensional articles prepared using additive manufacturing techniques.

Related Art Background

Conventionally, three-dimensional (3D) printing techniques of the "molten wire deposition" type use thermoplastic resins. The use of such resins limits the resolution that can be achieved to the width of a polymer bead that can be laid down. Additionally, articles prepared using thermoplastic resins and 3D printing processes suffer from poor adhesion between successive printed layers because the mobile polymer chains in the active layer (the layer that is printed) do not cannot re-entangle with the glassy polymer chains in the now cooled previous layer, creating points of mechanical weakness. Photocurable acrylic systems represent another type of resin that has been used for 3D printing of items, but such systems, when cured, typically exhibit high crosslink densities. This leads to articles with poor resistance to sudden stress and deformation, resulting in brittle failure. Therefore, photocurable acrylic resin systems have mainly only been used in prototyping applications.

The development of resin systems for use in 3D printing and other additive manufacturing applications that mitigate the aforementioned defects of known thermoplastic resin and photocurable acrylic formulations would thus be of great interest.

U.S. Patent No. 4,384,011 describes radiation-curable resin coating compositions containing, in a specific ratio, a soluble polyamide resin and a radiation-polymerizable monomer or the like dissolved in a solvent and the use of such compositions in processes for the production of resin gravure plates. Soluble polyamides suitable for such use include polyamides which have been modified by various types of reactions. In addition, the amount of soluble polyamide resin relative to the amount of radiation-polymerizable monomer compound is high (100 parts by weight of soluble polyamide resin per 50 to 100 parts by weight of radiation-polymerizable monomer compound).

WO 2018/033296 A1 describes polymerization-induced phase separation (PIPS) compositions for enhancing impact resistance and rheological properties in photocurable resins for 3D printing, such as for inks, coatings and adhesives. Such compositions are advantageous with respect to properties such as impact resistance, shear adhesion and cohesive strength. PIPS compositions can include X, Y, and Z components, X including an acrylic-based monomer; Y comprising a copolymer of a block A and a block B; and Z comprising a multifunctional crosslinking agent. Block copolymers which include polyamide type blocks are not disclosed.

EP 0919873 B1 describes a photocurable resin composition which comprises (A) an acid-modified, vinyl group-containing epoxy resin, (B) an elastomer (which may be a polyamide-based elastomer), (C) a light curing initiator, (D) a diluent and (E) a curing agent and which can provide a high performance cured film.

JP 2676662 B2 describes photocurable films which are made with low exposure by uniformly dissolving a photosensitive aromatic polyamide and a photopolymerization initiator in an organic solvent consisting essentially of a specific polyether compound. The composition containing a photosensitive polyamide is applied to a base material and the coating is dried to form the photosensitive thin film (dry film) containing the photosensitive aromatic polyamide and the photopolymerization initiator. The film is photocured by photoirradiation.

One aspect of the present invention provides an actinic radiation curable composition comprising:
a) at least one polyamide which does not contain functional groups curable by actinic radiation; And
b) at least one compound curable by actinic radiation, the at least one compound curable by actinic radiation being a liquid at 25°C;
condition i), condition ii) or condition iii) being satisfied:
i) the at least one polyamide is an unmodified polyamide or a combination of unmodified polyamides and the at least one polyamide is completely dissolved in the composition curable by actinic radiation at 25° C.;
ii) at least a portion of the at least one polyamide is present as dispersed particles in the composition curable by actinic radiation at 25°C;
iii) the actinic radiation curable composition is a gel at 25°C and a liquid at 100°C or more.

A method of making a cured polymeric material is also provided by the present invention, the method comprising curing the aforementioned actinic radiation curable composition using actinic radiation. A cured polymeric material obtained according to such a method is also another aspect of the invention.

A method of preparing a three-dimensional article by additive manufacturing (such as three-dimensional printing) is also provided by the present invention and includes using the actinic radiation-curable composition mentioned above to manufacture the three-dimensional article, as well as a three-dimensional article made by such a method.

The actinic radiation curable compositions of the present invention may be in the form of homogeneous solutions of polyamide in liquid matrices composed of one or more actinic radiation curable compounds. In other embodiments, at least a portion of the polyamide may be in the form of particles dispersed in a liquid matrix composed of one or more compounds curable by actinic radiation. Actinic radiation curable compositions can be rapidly cured using photochemical 3D printing techniques to provide high resolution articles that exhibit improved mechanical characteristics due to the presence of a polyamide as a component of the composition.

Brief Description of the Drawing

There is a plot of two Hansen parameters, namely the δh parameter (in MPa ^1/2 ), which quantifies the energy from intermolecular hydrogen bonds, against the δp parameter (also in MPa ^1/2 ), which represents the energy of intermolecular dipole interactions, for a number of compounds which are suitable for use herein as components (a) and (b).

Detailed Description of Embodiments of the Invention

Exemplary Characteristics of Actinic Radiation Curable Compositions

In accordance with desirable aspects of the present invention (particularly where the actinic radiation curable composition is intended for use in a manufacturing process, such as an additive manufacturing process, carried out at ambient temperatures), the actinic radiation curable composition actinic radiation is formulated to be a liquid at 25°C. For example, the actinic radiation curable composition may be a homogeneous liquid at 25°C. In other embodiments, however, the actinic radiation-curable composition is formulated to be a gel at 25°C, but a liquid at an elevated temperature (e.g., 120°C).

In embodiments where the polyamide or polyamides used in the composition are normally solid at 25°C, the polyamide or polyamides may be completely solubilized in the other components of the actinic radiation curable composition. However, according to other aspects of the invention, particles of the at least one polyamide are dispersed in a liquid matrix composed of at least one compound curable by actinic radiation. The polyamide component of the composition may be totally insoluble or only partially insoluble at 25°C. For example, according to various embodiments of the invention, 0%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70% , at least 80%, at least 90% or 100% by weight of the polyamide component is insoluble at 25°C. In embodiments wherein at least a portion of the polyamide component is in the form of non-solubilized dispersed particles, such particles may be stably dispersed in the liquid matrix of the at least one actinic radiation curable compound . The stability of the dispersion can be improved by the use of dispersants and/or the modification of the polyamide (for example, by modifying the polyamide to introduce functional groups which contribute to the stabilization of the dispersed polyamide particles).
Generally, it will be advantageous if the particle size of the dispersed polyamide particles is kept relatively small, for example, at d50 values below 300 µm, below 250 µm, or below 200 µm and/or at D90 values less than 400 µm, less than 350 µm, or less than 300 µm.

According to preferred embodiments of the invention, the composition curable by actinic radiation can have a viscosity at 25°C of not more than 100,000 mPa.s, not more than 50,000 mPa.s, not more than 25,000 mPa. s, not greater than 10,000 mPa.s, or not greater than 5,000 mPa.s, as measured with a Brookfield Viscometer, Model DV-II, using a 27 rod (the rod speed typically varying between 20 and 200 rpm, depending on viscosity). Relatively high viscosities can provide satisfactory performance in applications where the curable composition is heated above 25°C, such as in three-dimensional printing or similar operations which employ machines having heated resin vats.

Once cured by exposure to an effective amount of actinic radiation (such as ultraviolet or visible light or electron beam radiation), the actinic radiation-curable composition is transformed into a polymeric material. The polymeric material can be clear (transparent), translucent or opaque in appearance. Polyamide particles in a polymerized matrix from the actinic radiation curable compound(s) that are visible to the unaided human eye may be present. The polyamide can form domains in the polymeric material that are not visible to the unassisted human eye. For example, the polymeric material may comprise two phases, one phase being the polyamide and another phase being the cured reaction product of the actinic radiation curable compound(s). The polyamide could also be dispersed at the molecular level in the polymeric material. For example, the polymeric material may comprise an interpenetrating polymer network.

Polyamides

The actinic radiation curable compositions of the present invention contain one or more polyamides. As used herein, the term "polyamide" refers to a polymer in which amide bonds (-C(=O)NH-) occur along the molecular chain (i.e., along of the polymer backbone). However, as will be explained in more detail subsequently, the polymer backbone may additionally contain one or more other types of linkages in addition to amide linkages, such as, for example, ether linkages and/or ester linkages. In particular, the compositions include at least one polyamide that does not contain any actinic radiation-curable functional groups (i.e., functional groups capable of reacting when exposed to actinic radiation such that the polyamide becomes bonded covalently in the polymeric matrix formed by the curing induced by actinic radiation of the at least one compound curable by actinic radiation additionally present in the composition, such as compounds functionalized by (meth)acrylate). However, in some embodiments, the actinic radiation-curable composition may further comprise at least one polyamide bearing at least one actinic radiation-curable functional group.

According to some embodiments, the polyamide that contains no actinic radiation-curable functional groups (sometimes referred to herein as an "unfunctionalized polyamide") is an aliphatic polyamide. The unfunctionalized polyamide may, for example, have a number average molecular weight of at least 5,000 g/mole, at least 10,000 g/mole, at least 15,000 g/mole or at least 20,000g/mole. In other embodiments, the number average molecular weight of the unfunctionalized polyamide is no greater than 150,000 g/mole, 100,000 g/mole, or 75,000 g/mole. For example, unfunctionalized polyamides used in the present invention may have a number average molecular weight of 10,000 to 100,000 g/mole. Gel Permeation Chromatography (GPC) is used here to measure the number average molecular weight Mn according to ISO 16014-1:2012. The product is dissolved in hexafluoropropan-2-ol stabilized with 0.05 M potassium trifluoroacetate and maintained for 24 hours at room temperature at a concentration of 1 g/L. The solution obtained is then filtered on a PTFE membrane (porosity of 0.2 micrometer) and injected at a flow rate of 1 mL/min, into a liquid chromatographic system equipped with a set of PFG columns from Polymer Standards Service. The assembly consists of a guard column (dimensions 50 x 8 mm), a 1000 Å column (dimensions 300 x 8 mm, particle size 7 µm) and a 100 Å column (dimensions 300 x 8 mm, particle size 7 µm). The detection is made using the measurement of the refractive index. The molecular weights measured are given in PMMA equivalents (used for calibration).

Polyamides suitable for use in various aspects of the present invention can be modified polyamides. In various other aspects, polyamides which are unmodified polyamides are used. It is also possible to use combinations of one or more unmodified polyamides and one or more modified polyamides. As used herein, the term "modified polyamide" means a polyamide that has been modified by a chemical reaction to introduce new functional groups or substituents after being produced in a polymerization reaction. Typically, polymerizations to form polyamides involve condensation reactions in which one or more polyamines are reacted with one or more polycarboxylic acids (or equivalents thereof), condensation reactions involving both substituted monomers by amine and carboxylic acid groups, or the ring-opening polymerization of a cyclic lactam. Thus, an "unmodified polyamide" is a polyamide which is directly obtained by means of a polymerization reaction and which is not further reacted so as to introduce new functional groups or substituents into the polymer. If such an unmodified polyamide is subsequently reacted with one or more reactants in such a way that a chemical transformation takes place, then it is considered a modified polyamide.

In certain embodiments of the invention, the composition curable by actinic radiation is a homogeneous liquid at 25° C., the non-functionalized polyamide(s) used being completely soluble in the other components of the composition (in particular, completely soluble in the or the actinic radiation-curable compounds present in the composition). In such embodiments, the polyamide(s) and actinic radiation-curable compound or mixture of actinic radiation-curable compounds may be selected to have solubility parameters capable of providing the actinic radiation-curable composition as a homogeneous liquid. However, in other embodiments, the polyamide(s) may have only limited solubility at 25°C in the actinic radiation curable composition. In yet other embodiments, the unfunctionalized polyamide(s) are insoluble at 25°C in the other components of the actinic radiation curable composition. In embodiments where the polyamide(s) are not fully solubilized, the unsolubilized polyamide(s) or a corresponding unsolubilized portion may be present in the composition at 25°C in the form of particles, e.g. scattered particles.

According to certain advantageous embodiments of the invention, the actinic radiation-curable compound or the mixture of actinic radiation-curable compounds used as component (b) of the actinic radiation-curable composition is chosen on the basis of its parameters of Hansen's solubility, which reflect the physicochemical dissolution properties, also called solvation abilities, of organic substances. Hansen's solubility parameters can be calculated using the approach proposed by Charles Hansen in the work entitled "Hansen Solubility Parameters: A user's handbook", Second Edition (2007) Boca Raton, Fla.: CRC Press. ISBN 978-O-8493-7248-3. According to this approach, three parameters, called “Hansen's parameters”: δd, δp, and δh, are sufficient to predict the behavior of a solvent with respect to a given molecule. The parameter δd, in MPa ^1/2 , quantifies the energy of the forces of dispersion between the molecules, that is to say, the van der Waals forces. The parameter δp, in MPa ^1/2 , represents the energy of the intermolecular dipolar interactions. Finally, the parameter δh, in MPa ^1/2 , quantifies the energy resulting from intermolecular hydrogen bonds, that is to say, the ability to interact with a hydrogen bond. The sum of the squares of the three parameters corresponds to the square of the Hildebrand solubility parameter (δ _tot ). As is known in the art, Hansen's solubility parameters can be used as a means to predict whether one material will dissolve in another and form a solution. They are based on the idea that "like dissolves" where a molecule is defined to be "like" another if it binds to itself in a similar way. Hansen's three solubility parameters can thus be treated as coordinates in three-dimensional (Hansen's) space. The closer two molecules are to each other in this Hansen space, the higher the probability that they can form a solution together. The inventors have observed that the dispersion parameter δ _d , for the component of the non-functionalized polyamide type a) and the component curable by actinic radiation b) are sufficiently similar for the Hildebrand solubility parameter for each component to be mainly dependent on the parameters _δp , and _δh and so if these are plotted against each other in two-dimensional space they provide an indication of the solubility of the unfunctionalized polyamide component a) in the heat-curable component actinic radiation b).

All of the compounds shown in the accompanying figure may be suitable for use as components (a) and (b), as the case may be; other compounds (including, for example, other grades of PEBAX ^® elastomers) not shown in the figure may also be suitable for use as components (a) and (b). Component (a) and component (b), in certain embodiments of the invention, may have a Hansen solubility parameter δ _p of 7 to 10 MPa ^1/2 and a Hansen solubility parameter δ _h of 4.5 to 8.5 MPa ^1/2 . According to these embodiments and with reference to the figure, component (a) can be at least one of PEBAX® 2533, a polyamide 12 (PA12), PEBAX® 3533, PEBAX® 4033, and PEBAX ® 7433, and component (b) may be at least one of SR217, SR420, SR423D, SR506D, SR9075, SR504D, SR567P, SR261, SR789, SR285, SR239EU, and the CN1964CG. All these products are commercially available from the corresponding assignee.

In some embodiments, the actinic radiation-curable composition may be a 25°C gel that can be liquefied when heated (e.g., 80°C, 90°C, 100°C, 110°C , 120°C, 130°C, or 140°C) and/or when combined with an appropriate non-reactive solvent or combination of non-reactive solvents. At 25°C, the gel can be homogeneous, transparent and/or flexible. The actinic radiation-curable composition can be heated to reduce its viscosity for more convenient handling, during a 3D printing operation, for example. According to some embodiments, the actinic radiation-curable composition may be held in a compartment or vessel and heated to a temperature to reduce the viscosity of the actinic radiation-curable composition. For example, the actinic radiation-curable composition can be heated to a temperature above the melting point of component a).

According to certain embodiments, the composition comprises at least one thermoplastic polyamide. In other embodiments, the composition comprises at least one polyamide which is a thermoplastic elastomer.

The unfunctionalized polyamide can be a linear polyamide, according to various aspects of the invention. However, branched polyamides could also be used. The unfunctionalized polyamide can have terminal groups which are carboxylic acid groups, amine groups or both carboxylic acid groups and amine groups. Other types of end groups, other than actinic radiation curable end groups (e.g. (meth)acrylate type end groups) could also or alternatively be present.

Unfunctionalized polyamides suitable for use in the present invention include homopolymeric polyamides and copolymeric polyamides known in the art, such as, for example, polyamide 6,6, polyamide 6,10, polyamide 10,10, polyamide 6.12, a polyamide 4.6, a polyamide 6, a polyamide 11 and a polyamide 12.

Block copolymers composed of at least one polyamide block are also useful as unfunctionalized polyamides in the present invention. Such block copolymers further comprise at least one block which is not a polyamide block (sometimes referred to hereinafter as a non-polyamide block), such as, for example, at least one polyester block, at least one polyether- ester, at least one polyether block, or at least one polyorganosiloxane block. The at least one polyamide block can constitute a "hard" block (for example, a block having a glass transition temperature (Tg) of 30°C or more), while the at least one block different from a polyamide block can constitute a "soft" block (eg, a block having a Tg of less than 30°C, in particular a block having a Tg of 0°C or less).

Suitable polyamide blocks include homopolymeric polyamide blocks and copolymeric polyamide blocks known in the art, such as, for example, polyamide 6,6, polyamide 6,10, polyamide 10,10, polyamide 6,12, polyamide 4.6, a polyamide 6, a polyamide 11 and a polyamide 12.

The number average molecular weight of the block(s) is not particularly limited and may be varied as desired in order to impart certain characteristics to the actinic radiation curable composition and/or the cured product obtained therefrom. For example, the polyamide block or blocks may have a number average molecular weight of at least 400 g/mole or at least 500 g/mole and/or a number average molecular weight of no more than 20,000 g/mole. mole or not greater than 1000 g/mole. According to certain embodiments, the number-average molecular weight of the polyamide block(s) can be from 400 to 20,000 g/mole or 500 to 10,000 g/mole.

As mentioned previously, the non-polyamide block(s) can, for example, be chosen from the group consisting of polyether blocks (blocks containing a plurality of ether bonds in the polymer backbone), polyester blocks (blocks containing a plurality of ester bonds in the polymer backbone, polyether-ester blocks (blocks containing a plurality of both ether and ester bonds in the polymer backbone) and polyorganosiloxane blocks (blocks containing a plurality of –O-Si(R ) ₂ - in the polymer backbone, each R being an organic moiety such as a methyl group).Thus, block polymers useful in the present invention include, but are not limited to, polyamide-polyether block copolymers, polyamide-polyester block copolymers, polyamide-polyether-polyester block copolymers, and polyamide-polyorganosiloxane block copolymers.

Suitable polyether blocks include in particular polyoxyalkylene blocks such as blocks formed by the ring-opening polymerization of alkylene oxides such as ethylene oxide, propylene oxide, oxetane and tetrahydrofuran. In some embodiments, the polyoxyalkylene block(s) are homopolymeric (i.e., contain repeating units that are identical in structure), but copolymer blocks composed of two or more different oxyalkylene repeating units are also possible. Suitable polyether blocks include, but are not limited to, polyethylene glycol blocks (which may also be referred to as polyoxyethylene blocks) polypropylene glycol blocks (which may also be referred to as polyoxypropylene blocks), polytrimethylene glycol blocks (which may also be referred to as polyoxytrimethylene blocks) , and polytetramethylene glycol blocks (which may also be referred to as polyoxytetramethylene blocks). The polyether block could also be a block containing a central non-ether moiety, such as a bisphenol moiety, which is substituted with polyoxyalkylene moieties (such as polyoxyethylene moieties). For example, the polyether block could be an ethoxylated bisphenol A block.

One or more polyester blocks could also be present in a suitable polyamide for use in the present invention, the polyamide being a block copolymer. Such polyester blocks can be aliphatic polyester blocks, although aromatic polyester blocks could also be used.

In yet other embodiments, the non-polyamide block(s) could be a polyorganosiloxane block, such as a polydimethylsiloxane block.

The number average molecular weight of the non-polyamide block(s) is not particularly limited and can be varied as desired in order to impart certain characteristics to the actinic radiation curable composition and/or the cured product obtained therefrom . For example, the non-polyamide block(s) may have a number average molecular weight of at least 200 g/mole or at least 300 g/mole and/or a number average molecular weight of no more than 6000 g /mole or not greater than 3000 g/mole. According to certain embodiments, the number average molecular weight of the non-polyamide block or blocks can be from 200 to 6000 g/mole or from 300 to 3000 g/mole.

The block copolymer comprising at least one polyamide block and at least one non-polyamide block may comprise, for example, from 5 to 95% by weight of polyamide blocks and from 5 to 95% by weight of non-polyamide blocks, from 10 to 90% by weight of polyamide blocks and from 10 to 90% by weight of non-polyamide blocks, or from 15 to 85% by weight of polyamide blocks and from 15 to 85% by weight of non-polyamide blocks, on the basis the weight of the block copolymer.

In some embodiments, the polyamide is a block copolymer containing a single non-polyamide block (e.g., a polyether or polyester block) and two polyamide blocks, the non-polyamide block forming a central block and the polyamide blocks forming terminal blocks having the general ABA structure in which A=polyamide block and B=non-polyamide block. However, in other embodiments, the polyamide is a block copolymer containing a single non-polyamide block and a single polyamide block having the general structure AB in which A = polyamide block and B = polyether block. In still other embodiments, the non-functionalized polyamide is a multiblock copolymer containing two or more non-polyamide blocks and two or more polyamide blocks arranged alternately and corresponding to the general structure (AB) _n in which A = block polyamide, B = non-polyamide block, and n = an integer of 2 or more.

Methods for preparing block copolymers containing one or more polyamide blocks and one or more non-polyamide blocks are well known in the art and any of such methods can be used to prepare polyamide block copolymers for use in the present invention.

Exemplary polyamide block copolymers suitable for use in the present invention are described, for example, in the following published patent applications: US 2015/0166746 A1; US 2016/0369098 A1; and US 2016/0251484 A1.

Combinations of two or more different polyamides can be used in the present invention. The term "polyamide component" as used herein refers to all constituents of the actinic radiation curable composition which are polyamides (whether a single polyamide or a combination of polyamides).

The amount of polyamide component present in the actinic radiation curable composition can be varied as desired or as necessary in order to achieve properties or characteristics in the actinic radiation curable composition and/or a cured product obtained therefrom. these as a result of curing by exposure to actinic radiation. For example, the actinic radiation curable composition may comprise at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 5 wt%, or at least 10 wt% polyamide based on the total weight of the actinic radiation curable composition. According to some embodiments, the actinic radiation-curable composition may be composed of no more than 50 wt%, no more than 40 wt%, or no more than 30 wt% polyamide based on the total weight of the composition curable by actinic radiation.

In other aspects of the invention, the actinic radiation-curable composition comprises up to 30 parts by weight of polyamide per 100 parts by weight of actinic radiation-curable compound (when more than one actinic radiation-curable compound is present , per 100 parts by weight of the total amount of actinic radiation-curable compounds). In other aspects, the actinic radiation-curable composition may comprise at least 0.5 parts by weight of polyamide per 100 parts by weight of actinic radiation-curable compound. For example, in some embodiments, the actinic radiation curable composition may comprise 0.5 to 25 parts by weight of polyamide per 100 parts by weight of actinic radiation curable compound.

Actinic Radiation Curable Compounds

The actinic radiation curable compositions of the present invention contain, in addition to one or more polyamides, one or more actinic radiation curable compounds. Such actinic radiation curable compounds include compounds containing one or more functional groups which are capable of participating in polymerization or curing reactions when exposed to actinic radiation such that a polymeric matrix is formed as a result of a covalent bond involving functional groups on several individual molecules of such compounds. Functional groups suitable for such a purpose include ethylenically unsaturated functional groups such as (meth)acrylate functional groups (i.e., acrylate functional groups, methacrylate functional groups), (meth)acrylamide functional groups (i.e., acrylamide functional groups, methacrylamide functional groups), cyanoacrylate functional groups, methylidene malonate functional groups, itaconate type functional groups, vinyl type functional groups, vinyl ether type functional groups and the like. An actinic radiation curable compound used in the present invention may have one such actinic radiation curable functional group per molecule or two, three, four or more actinic radiation curable functional groups per molecule. If the actinic radiation-curable compound contains two or more actinic radiation-curable functional groups per molecule, such functional groups may be the same or different from each other.

Actinic radiation-curable compounds can be monomeric or oligomeric in character, as described below in more detail. Suitable (meth)acrylate-functionalized compounds, for example, include both (meth)acrylate-functionalized monomers and (meth)acrylate-functionalized oligomers.

According to some embodiments of the invention, the actinic radiation curable composition comprises at least one (meth)acrylate functionalized monomer or oligomer containing two or more (meth)acrylate functional groups per molecule. Examples of useful (meth)acrylate functionalized monomers containing two or more (meth)acrylate functional groups per molecule include acrylate and methacrylate esters of polyhydric alcohols (organic compounds containing two or more hydroxyl groups per molecule , e.g. 2 to 6). Specific examples of suitable polyhydric alcohols include C2-20 alkylene glycols (glycols having a C2-10-alkylene group may be preferred, in which the carbon chain may be branched; e.g. ethylene glycol, trimethylene glycol, 1,2-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, tetramethylene glycol (1,4-butanediol), 1,5-pentanediol, 1,6-hexanediol , 1,8-octanediol, 1,9-nonanediol, 1,12-dodecanediol, cyclohexane-1,4-dimethanol, bisphenols, and hydrogenated bisphenols, as well as alkoxylated derivatives thereof (e.g. g., ethoxylated and/or propoxylated), in which for example 1 to 20 moles of an alkylene oxide such as ethylene oxide and/or propylene oxide have been reacted with 1 mole of glycol), diethylene glycol, glycerin, alkoxylated glycerin, triethylene glycol, dipropylene glycol, tripropylene glycol, trimethylolpropane, alkoxylated trimethylolpropane, ditr iméthylolpropane, le ditriméthylolpropane alcoxylé, le pentaérythritol, le pentaérythritol alcoxylé, le dipentaérythritol, le dipentaérythritol alcoxylé, un cyclohexanediol, un cyclohexanediol alcoxylé, un cyclohexanediméthanol, un cyclohexanediméthanol alcoxylé, un norbornènediméthanol, un norbornènediméthanol alcoxylé, un norbornanediméthanol, un norbornanediméthanol alcoxylé, des polyols containing an aromatic ring, adducts of cyclohexane-1,4-dimethanol and ethylene oxide, adducts of bisphenol and ethylene oxide, adducts of hydrogenated bisphenol and ethylene oxide, adducts bisphenol and propylene oxide, hydrogenated bisphenol and propylene oxide adducts, cyclohexane-1,4-dimethanol and propylene oxide adducts, sugar alcohols and alkoxylated sugar alcohols. Such polyhydric alcohols can be fully or partially esterified (with a (meth)acrylic acid, a (meth)acrylic anhydride, a (meth)acryloyl chloride or the like), provided that they contain at least two functional groups of the type (meth)acrylate per molecule. As used herein, the term "alkoxylated" refers to compounds in which one or more epoxides such as ethylene oxide and/or propylene oxide have been reacted with compounds containing an active hydrogen. (eg, hydroxyl groups) of a base compound, such as a polyhydric alcohol, to form one or more oxyalkylene moieties. For example, 1 to 25 moles of epoxide can react per mole of base compound. According to certain aspects of the invention, the functionalized monomer(s) of the (meth)acrylate type used can be of a relatively low molecular weight (eg, 100 to 1000 g/mole).

Any (meth)acrylate functionalized oligomer known in the art can also be used in the actinic radiation curable compositions of the present invention. In some embodiments, such oligomers contain two or more (meth)acrylate functional groups per molecule. The number average molecular weight of such oligomers can vary widely, e.g., from about 500 to about 50,000.

Suitable (meth)acrylate functionalized oligomers include, for example, polyester (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyether (meth)acrylate oligomers, polyurethane (meth)acrylate oligomers , acrylic (meth)acrylate oligomers, polydiene (meth)acrylate oligomers, polycarbonate (meth)acrylate oligomers, polyamide (meth)acrylate oligomers and combinations thereof. Such oligomers can be selected and used in combination with one or more (meth)acrylate functionalized monomers to adjust or refine the properties of a cured resin prepared using the actinic radiation curable composition of present invention.

Exemplary polyester (meth)acrylate oligomers include reaction products of acrylic or methacrylic acid or mixtures thereof with hydroxyl-terminated polyester polyols. The reaction process can be conducted such that all, or nearly all, of the hydroxyl groups of the polyester polyol have been (meth)acrylated, particularly in cases where the polyester polyol is difunctional. Polyester polyols can be prepared by polycondensation reactions of polyhydroxy compounds (particularly diols) and polycarboxylic acid compounds (particularly dicarboxylic acids and anhydrides). The polyhydroxy and polycarboxylic acid components can each have linear, branched, cycloaliphatic or aromatic structures and can be used individually or as mixtures.

Examples of suitable epoxy (meth)acrylate oligomers include reaction products of acrylic or methacrylic acid or mixtures thereof with glycidyl ethers or esters.

Suitable polyether (meth)acrylate oligomers include, but are not limited to, condensation reaction products of acrylic or methacrylic acid or mixtures thereof with polyetherols which are polyether polyols (such as a polyethylene glycol, a polypropylene glycol or a polytetramethylene glycol). Suitable polyetherols can be linear or branched substances containing ether linkages and terminal hydroxyl groups. Polyetherols can be prepared by ring-opening polymerization of cyclic ethers such as tetrahydrofuran or alkylene oxides with a starting molecule. Suitable starting molecules include water, polyhydroxyl functionalized materials, polyester polyols and amines.

Polyurethane (meth)acrylate oligomers (sometimes also referred to as "urethane (meth)acrylate oligomers") suitable for use in the multicomponent systems of the present invention include aliphatic polyester polyol and polyether polyol-based urethanes and /or aromatics and aliphatic and/or aromatic polyester diisocyanates and polyether diisocyanates capped with terminal (meth)acrylate groups. Suitable polyurethane (meth)acrylate oligomers include, for example, aliphatic polyester-based urethane diacrylate and tetraacrylate oligomers, aliphatic polyether-based urethane diacrylate and tetraacrylate oligomers, as well as polyether-based urethane diacrylate and tetraacrylate oligomers. aliphatic polyester/polyether based urethane.

In various embodiments, the polyurethane (meth)acrylate oligomers can be prepared by reacting aliphatic and/or aromatic diisocyanates with OH-terminated polyester polyols (including aromatic, aliphatic, and mixed aliphatic polyester polyols). /aromatic), polyether polyols, polycarbonate polyols, polycaprolactone polyols, polydimethylsiloxane polyols, or polybutadiene polyols, or combinations thereof to form isocyanate-functionalized oligomers which are then reacted with (meth) hydroxyl functionalized acrylates such as hydroxyethyl acrylate or hydroxyethyl methacrylate to provide terminal (meth)acrylate groups. For example, polyurethane (meth)acrylate oligomers can contain two, three, four or more (meth)acrylate functional groups per molecule.

Suitable acrylic (meth)acrylate oligomers (sometimes also referred to in the art as "acrylic oligomers") include oligomers which can be described as substances having an oligomeric acrylic backbone which is functionalized with one or more groups (meth )acrylate (which may be at an end of the oligomer or pendant to the acrylic skeleton). The acrylic backbone can be a homopolymer, a random copolymer or a block copolymer composed of repeating units of acrylic type monomers. The acrylic type monomers can be any monomeric (meth)acrylate such as C1-C6 alkyl (meth)acrylates as well as functionalized (meth)acrylates such as (meth)acrylates carrying hydroxyl groups, carboxylic acid and/or epoxy. The acrylic (meth)acrylate oligomers can be prepared using any procedure known in the art, such as oligomerization of monomers, at least a portion of which being functionalized with hydroxyl, carboxylic acid, and/or epoxy (e.g., hydroxyalkyl (meth)acrylates, (meth)acrylic acid, glycidyl (meth)acrylate) to obtain a functionalized oligomer intermediate, which is then reacted with a or more reactants containing a (meth)acrylate to introduce the desired (meth)acrylate functional groups.

Exemplary (meth)acrylate functionalized monomers and oligomers may include ethoxylated bisphenol A di(meth)acrylates; triethylene glycol di(meth)acrylate; ethylene glycol di(meth)acrylate; tetraethylene glycol di(meth)acrylate; polyethylene glycol di(meth)acrylates; 1,4-butanediol diacrylate; 1,4-butanediol dimethacrylate; diethylene glycol diacrylate; diethylene glycol dimethacrylate; 1,6-hexanediol diacrylate; 1,6-hexanediol dimethacrylate; neopentyl glycol diacrylate; a neopentylglycol di(meth)acrylate; a polyethylene glycol dimethacrylate (600) (where 600 refers to the approximate number average molecular weight of the polyethylene glycol part); a polyethylene glycol diacrylate (200); 1,12-dodecanediol dimethacrylate; tetraethylene glycol diacrylate; triethylene glycol diacrylate; 1,3-butylene glycol dimethacrylate; tripropylene glycol diacrylate; a polybutadiene diacrylate; methylpentanediol diacrylate; a polyethylene glycol diacrylate (400); ethoxylated bisphenol A dimethacrylate ₂ ; _3- ethoxylated bisphenol A dimethacrylate; ethoxylated bisphenol A diacrylate ₃ ; cyclohexanedimethanol dimethacrylate; cyclohexanedimethanol diacrylate; _ethoxylated bisphenol A dimethacrylate (where the number following "ethoxylated" is the average number of oxyalkylene moieties per molecule); dipropylene glycol diacrylate; ethoxylated bisphenol A dimethacrylate ₄ ; ethoxylated bisphenol A dimethacrylate ₆ ; ethoxylated bisphenol A dimethacrylate ₈ ; alkoxylated hexanediol diacrylates; an alkoxylated cyclohexanedimethanol diacrylate; dodecane diacrylate; ethoxylated bisphenol A diacrylate ₄ ; ethoxylated bisphenol A diacrylate ₁₀ ; a polyethylene glycol dimethacrylate (400); a polypropylene glycol dimethacrylate (400); metal diacrylates; modified metal diacrylates; metal dimethacrylates; polyethylene glycol dimethacrylate (1000); a methacrylated polybutadiene; _2- propoxylated neopentylglycol diacrylate; ethoxylated bisphenol A dimethacrylate ₃₀ ; ethoxylated bisphenol A diacrylate ₃₀ ; alkoxylated neopentylglycol diacrylates; polyethylene glycol dimethacrylates; 1,3-butylene glycol diacrylate; ethoxylated bisphenol A dimethacrylate ₂ ; dipropylene glycol diacrylate; ethoxylated bisphenol A diacrylate ₄ ; a polyethylene glycol diacrylate (600); polyethylene glycol dimethacrylate (1000); tricyclodecaneimethanol diacrylate; propoxylated neopentylglycol diacrylates such as propoxylated neopentylglycol diacrylate ₂ ; alkoxylated aliphatic alcohol diacrylates; trimethylolpropane trimethacrylate; trimethylolpropane triacrylate; tris(2-hydroxyethyl) isocyanurate triacrylate; ethoxylated trimethylolpropane triacrylate20; pentaerythritol triacrylate; ethoxylated trimethylolpropane triacrylate ₂₀ ; pentaerythritol triacrylate; ethoxylated trimethylolpropane triacrylate ₃ ; _3- propoxylated trimethylolpropane triacrylate; ethoxylated trimethylolpropane triacrylate ₆ ; _6- propoxylated trimethylolpropane triacrylate; ethoxylated trimethylolpropane triacrylate ₉ ; alkoxylated trifunctional acrylate esters; trifunctional methacrylate esters; trifunctional acrylate esters; _3- propoxylated glyceryl triacrylate; _5,5- propoxylated glyceryl triacrylate; ethoxylated trimethylolpropane triacrylate ₁₅ ; trifunctional phosphoric acid esters; trifunctional acrylic acid esters; pentaerythritol tetraacrylate; ditrimethylolpropane tetraacrylate; _4- ethoxylated pentaerythritol tetraacrylate; a polyoxyethylene pentaerythritol tetraacrylate; dipentaerythritol pentaacrylate; pentaacrylate esters; epoxy acrylate oligomers; epoxy methacrylate oligomers; urethane acrylate oligomers; urethane methacrylate oligomers; polyester acrylate oligomers; polyester methacrylate oligomers; a stearyl methacrylate oligomer; acrylic acrylate oligomers; perfluorinated acrylate oligomers; perfluorinated methacrylate oligomers; amine acrylate oligomers; amine modified polyether acrylate oligomers; and amine methacrylate oligomers.

The actinic radiation curable compositions of the present invention may comprise one or more (meth)acrylate functionalized compounds containing a single acrylate or methacrylate functional group per molecule (referred to herein as "mono(meth)acrylate functionalized compounds"). Any of these compounds known in the art can be used.

Examples of suitable mono(meth)acrylate functionalized compounds include, but are not limited to, mono(meth)acrylate esters of aliphatic alcohols (the aliphatic alcohol may be straight chain, branched or alicyclic and may be a monoalcohol, a dialcohol or a polyalcohol, provided that only one hydroxyl group is esterified with a (meth)acrylic acid); mono(meth)acrylate esters of aromatic alcohols (such as phenols, including alkylated phenols); mono(meth)acrylate esters of alkylaryl alcohols (such as benzyl alcohol); mono(meth)acrylate esters of oligomeric and polymeric glycols such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, a polyethylene glycol, and a polypropylene glycol); mono(meth)acrylate esters of monoalkyl ethers of glycols, oligomeric glycols, polymeric glycols; mono(meth)acrylate esters of alkoxylated (e.g., ethoxylated and/or propoxylated) aliphatic alcohols (the aliphatic alcohol may be straight chain, branched or alicyclic and may be a monoalcohol, a dialcohol or a polyalcohol, provided that only one hydroxyl group of the alkoxylated aliphatic alcohol is esterified with a (meth)acrylic acid); mono(meth)acrylate esters of aromatic alcohols (such as alkoxylated phenols) alkoxylated (e.g., ethoxylated and/or propoxylated); caprolactone mono(meth)acrylates; and similar.

The following compounds are specific examples of mono(meth)acrylate functionalized compounds suitable for use in the curable compositions of the present invention: methyl (meth)acrylate; ethyl (meth)acrylate; n-propyl (meth)acrylate; n-butyl (meth)acrylate; isobutyl (meth)acrylate; n-hexyl (meth)acrylate; 2-ethylhexyl (meth)acrylate; n-octyl (meth)acrylate; isooctyl (meth)acrylate; n-decyl (meth)acrylate; n-dodecyl (meth)acrylate; tridecyl (meth)acrylate; tetradecyl (meth)acrylate; hexadecyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate; 2-hydroxypropyl (meth)acrylate and 3-hydroxypropyl (meth)acrylate; 2-methoxyethyl (meth)acrylate; 2-ethoxyethyl (meth)acrylate; 2-ethoxypropyl (meth)acrylate and 3-ethoxypropyl (meth)acrylate; tetrahydrofurfuryl (meth)acrylate; alkoxylated tetrahydrofurfuryl (meth)acrylate; isobornyl (meth)acrylate; 2-(2-ethoxyethoxy)ethyl (meth)acrylate; cyclohexyl (meth)acrylate; glycidyl (meth)acrylate; isodecyl (meth)acrylate; 2-phenoxyethyl (meth)acrylate; lauryl (meth)acrylate; isobornyl (meth)acrylate; 2-phenoxyethyl (meth)acrylate; alkoxylated phenol (meth)acrylates; alkoxylated nonylphenol (meth)acrylates; cyclic trimethylolpropane formal (meth)acrylate; trimethylcyclohexanol (meth)acrylate; diethylene glycol monomethyl ether (meth)acrylate; diethylene glycol monoethyl ether (meth)acrylate; diethylene glycol monobutyl ether (meth)acrylate; triethylene glycol monoethyl ether (meth)acrylate; ethoxylated lauryl (meth)acrylate; methoxypolyethylene glycol (meth)acrylates; and combinations thereof.

Photoinitiators

In certain embodiments of the invention, the actinic radiation-curable compositions described herein include at least one photoinitiator and are curable by radiant energy (visible light, ultraviolet light). A photoinitiator can be considered as any type of substance which, upon exposure to radiation (e.g., actinic radiation), forms species which initiate the reaction and curing of polymerizing organic substances present in the curable composition . Suitable photoinitiators include both free radical photoinitiators as well as cationic photoinitiators and combinations thereof.

Free radical polymerization initiators are substances that form free radicals when irradiated. The use of free radical photoinitiators is particularly preferred. Non-limiting types of free radical photoinitiators suitable for use in the curable compositions of the present invention include, for example, benzoins, benzoin ethers, acetophenones, benzil, benzil ketals, anthraquinones, oxides phosphine compounds, α-hydroxyketones, phenylglyoxylates, α-aminoketones, benzophenones, thioxanthones, xanthones, acridine derivatives, phenazene derivatives, quinoxaline derivatives and triazine derivatives.

If a photoinitiator is present in the actinic radiation curable composition, typical concentrations are up to about 15% by weight based on the total weight of the curable composition. For example, the actinic radiation-curable composition may comprise from 0.1 to 10% by weight, in total, of photoinitiator, based on the total weight of the curable composition.

Non-Reactive Solvent

According to certain embodiments of the invention, the actinic radiation-curable composition is formulated to be free of, or substantially free of, a non-reactive solvent. As used herein, the term "non-reactive solvent" refers to a solvent which is not capable of being cured by actinic radiation, unlike the actinic radiation-curable compound(s) present in the composition. However, the non-reactive solvent could react with one or more components of the composition by other mechanisms.

For example, the actinic radiation curable composition may include less than 5 wt%, less than 2 wt%, less than 1 wt%, less than 0.5 wt%, 0.1 wt% point or even 0% by weight of non-reactive solvent, based on the total weight of the composition.

However, for some applications it may be desirable to include a significant amount of one or more non-reactive solvents in the actinic radiation curable composition. For example, a non-reactive solvent can be used to help solubilize one or more components of the composition (in particular, the polyamide component) and/or to reduce the viscosity of the composition. The type of non-reactive solvent that could be used is not limited, provided it does not interfere with the ability to cure the composition by exposing it to actinic radiation. Suitable non-reactive solvents include, for example, ketones (eg, acetone), esters, ethers, alcohols (including halogenated alcohols, such as fluorinated alcohols, aromatic hydrocarbons, and the like) and combinations thereof. The actinic radiation curable composition could, for example, be formulated to include at least 0.5 wt%, at least 1 wt%, at least 2 wt%, or at least 5 wt% of one or more non-reactive solvents, based on the total weight of the composition. In other embodiments, the actinic radiation curable composition comprises up to 90 wt%, up to 80 wt%, up to 70 wt%, up to 60 wt%, up to 50% by weight, up to 40% by weight, up to 30% by weight, up to 25% by weight or up to 20% by weight of non-reactive solvent(s), based on of the total weight of the composition. For example, the actinic radiation curable composition may comprise 1-50% or 1-25% by weight non-reactive solvent.

If present, the non-reactive solvent could be either a volatile non-reactive solvent or a non-volatile reactive solvent. As used herein, the term "volatile" means a substance having a boiling point at atmospheric pressure not greater than 100°C and the term "non-volatile" means a substance having a boiling point at atmospheric pressure greater than 100°C. Combinations of volatile and non-volatile solvents could also be employed.

The use of one or more non-reactive solvents to help solubilize certain components (in particular the polyamide component) during the formulation of the composition is also included within the scope of the present invention, where after the components of the composition (including the non-reactive solvent(s)) have been combined, at least a portion of the non-reactive solvent is then removed to provide the final formulated actinic radiation curable composition suitable for use in the desired application (e.g. additive manufacturing). For example, the components of the composition can be combined and then subjected to process steps such as mixing and/or heating to obtain a homogeneous product or solution, at least a portion of the non-reactive solvent then being removed by a suitable means such as distillation or vacuum stripping.

Other Possible Additives

Depending on the particular intended end application and desired properties of the actinic radiation curable composition and the cured product obtained therefrom, one or more other additives may optionally be present in the composition. Such additives can, for example, be chosen from the group consisting of chain transfer agents, light blocking agents (photoblocking agents), wetting agents (surface tension modifiers), matting agents, colorants, dyes, pigments, adhesion promoters, fillers, rheology modifiers/agents, flow or leveling agents, thixotropic agents, plasticizers, light absorbers, light stabilizers, dispersants, antioxidants, antistatic agents, lubricants, opacifying agents, antifoaming agents, polymerization inhibitors, and combinations thereof, including all additives conventionally used in the art of coatings, sealants, adhesives, castings, 3D printing, additive manufacturing or inks.

The actinic radiation curable compositions of the present invention may include one or more light blocking agents (sometimes referred to as absorbers in the art), particularly when the curable composition is to be used as a resin in a three-dimensional printing process involving photocuring. of the curable composition. The light blocking agent or agents can be any substance known in the art of three-dimensional printing, including, for example, non-reactive pigments and non-reactive dyes. The light blocking agent can be a visible light blocking agent or a UV light blocking agent, for example. Examples of suitable light blocking agents include, but are not limited to, titanium dioxide, carbon black, and organic ultraviolet light absorbers such as hydroxybenzophenone, hydroxyphenylbenzotriazole, oxalanilide, benzophenone, thioxanthone, a hydroxyphenyltriazine, Sudan I, bromothymol blue, 2,2'-(2,5-thiophenediyl)bis(5-tert-butylbenzoxazole) (sold under the trade name "Benetex OB Plus") and absorbers benzotriazole type ultraviolet light.

The amount of light blocking agent can be varied as desired or appropriate for particular applications. Generally, if the actinic radiation curable composition contains a light blocking agent, it is present in a concentration ranging from 0.001 to 10% by weight based on the weight of the curable composition.

Preparation Processes

The actinic radiation curable compositions of the present invention can be prepared by any suitable method. For example, the various desired components can simply be combined and mixed. When it is desired to obtain a certain level of solubilization of the polyamide component, such solubilization can be facilitated by various means, such as, for example, heating of the combined components and/or vigorous agitation of the combined components. Homogenization processes could also be employed. Additionally, one or more solvents could be used to facilitate dissolution of the polyamide component, as previously described. In one embodiment, a finely powdered polyamide is slowly added to the other components of the composition at a temperature of 20°C to 90°C while mixing. The resulting actinic radiation curable composition can then be stored under suitable protective conditions until it is desired to use it to form a cured article or product therefrom.

Uses of Actinic Radiation Curable Compositions

As mentioned previously, actinic radiation curable compositions prepared in accordance with the present invention may contain one or more photoinitiators and may be photocurable. In certain other embodiments of the invention, the actinic radiation-curable compositions described herein do not include an initiator and are curable (at least in part) by electron beam energy.

The actinic radiation curable compositions described herein may be compositions which are to be cured by means of free radical polymerization, cationic polymerization or other types of polymerization. In particular embodiments, the curable compositions are photocured (i.e., cured by exposure to actinic radiation such as light, especially visible or UV light). End applications for curable compositions include, but are not limited to, inks, coatings, adhesives, additive manufacturing resins (such as 3D printing resins), molding resins, sealants , composites, antistatic layers, electronic applications, recyclable materials, intelligent materials capable of detecting and responding to stimuli, and biomedical materials. The actinic radiation curable compositions described herein may be suitable for the process known as 3D hot printing, where the composition may be extruded in a manner similar to 3D fabrication by a fused filament process and simultaneously cured. , or subsequently hardened by actinic radiation. Any 3D printing process as described here can be done at an appropriate temperature to achieve a desirable viscosity.

Cured compositions prepared from the actinic radiation curable compositions as described herein can be used, for example, in three-dimensional articles (the three-dimensional article may consist essentially of, or consist of, the cured composition), coated articles (a substrate being coated with one or more layers of the cured composition, including encapsulated articles in which a substrate is completely enveloped by the cured composition), laminated or bonded articles (a first component of the article being laminated or bonded to a second component by means of the cured composition), composite articles or printed articles (graphics or the like being printed on a substrate, such as a substrate containing paper, plastic and/or metal, at the using the cured composition).

The curing of the compositions curable by actinic radiation in accordance with the present invention can be implemented by any suitable process, such as polymerization by free radical and/or cationic route. One or more initiators, such as a free radical initiator (eg, a photoinitiator that generates free radical-like species when irradiated), may be present in the actinic radiation curable composition. Prior to curing, the actinic radiation-curable composition may be applied to a surface of a substrate in any known conventional manner, for example, by spray coating, knife coating, roller coating, casting, drumming, dipping, and the like and combinations thereof. An indirect application using a transfer process can also be used. Application to a substrate surface can be done at ambient (e.g., room) or elevated temperature. For example, if the actinic radiation-curable composition is a solid (such as a gel) at room temperature, it could be heated to a temperature effective to liquefy the actinic radiation-curable composition to facilitate application to the surface of a substrate. Such embodiments of the present invention may be used, for example, in three-dimensional printing or similar operations which employ machines having heated resin vats or compartments, or in processes where the actinic radiation-curable composition may be extruded and then subsequently cured, or cured during the extrusion step.

A substrate can be any commercially relevant substrate, such as a high surface energy substrate or a low surface energy substrate, respectively such as a metallic substrate or a plastic substrate. Substrates can include metal, paper, cardboard, glass, thermoplastics such as polyolefins, polycarbonate, acrylonitrile butadiene styrene (ABS), and mixtures thereof, composites, wood, leather and combinations thereof. When used as an adhesive, the actinic radiation curable composition can be placed between two substrates and then cured, the cured composition thereby bonding the substrates together to provide a bonded article. Actinic radiation-curable compositions in accordance with the present invention may also be formed or cured in bulk (eg, the actinic radiation-curable composition may be cast into a suitable mold and then cured).

Curing can be accelerated or facilitated by supplying energy to the actinic radiation curable composition, for example by exposing the actinic radiation curable composition to a source of radiation, such as visible or UV light, a infrared radiation and/or electron beam radiation. Thus, the cured composition can be considered to be the reaction product of the actinic radiation curable composition, formed by curing. A curable composition can be partially cured by exposure to actinic radiation, further curing being achieved by heating the partially cured article. For example, an article formed from the curable composition (e.g., a 3D printed article) can be heated to a temperature ranging from 40°C to 120°C for a period of time ranging from 5 minutes to 12 hours .

A plurality of layers of an actinic radiation curable composition in accordance with the present invention can be applied to a surface of a substrate; the plurality of layers may be simultaneously cured (by exposure to a single dose of radiation, for example) or each layer may be sequentially cured prior to the application of an additional layer of the actinic radiation curable composition.

The actinic radiation curable compositions described herein can be used as resins in three-dimensional printing applications. Three-dimensional (3D) printing (which is a type of additive manufacturing) is a process in which a 3D digital model is made by the accumulation of building material. The printed 3D object is created using computer-aided design (CAD) data of an object by sequentially building two two-dimensional (2D) layers or slices that correspond to cross-sections of 3D objects. Stereolithography (SL) is a type of additive manufacturing in which a liquid resin is hardened by selective exposure to radiation to form each 2D layer. The radiation can be in the form of electromagnetic waves or an electron beam. The most commonly applied energy source is ultraviolet, visible or infrared radiation.

The actinic radiation curable compositions of the invention described herein can be used as resin formulations for 3D printing, i.e. compositions intended for use in the manufacture of three-dimensional articles using printing techniques. 3D printing. Such three-dimensional articles may be self-contained/self-supporting and may consist essentially of, or consist of, an actinic radiation-curable composition in accordance with the present invention which has been cured. The three-dimensional article can also be a composite, comprising at least one component consisting essentially of, or consisting of, a cured composition as mentioned above as well as at least one additional component composed of one or more materials different from a such hardened composition (for example, a metal component or a thermoplastic component). The actinic radiation curable compositions of the present invention are particularly useful in digital light printing (DLI), although other types of three-dimensional (3D) printing processes can also be practiced using the curable compositions. of the invention (eg, SLA, inkjet). The actinic radiation curable compositions of the present invention can be used in a three-dimensional printing operation together with another material that functions as a frame or support for the article formed from the actinic radiation curable composition of the present invention. invention.

Thus, the actinic radiation-curable compositions of the present invention are useful in the practice of various types of three-dimensional manufacturing or printing techniques, including methods in which the construction of a three-dimensional object is achieved in stages or layer after layer. In such processes, layer formation may be accomplished by solidifying (curing) the actinic radiation-curable composition under the action of exposure to radiation, such as irradiation with visible light, UV or other actinic irradiation. For example, new layers can be formed at the upper surface of the growing object or at the lower surface of the growing object. The actinic radiation-curable compositions of the present invention can also be advantageously employed in processes for the production of three-dimensional objects by additive manufacturing in which the process is carried out continuously. For example, the object can be produced from a liquid interface. Suitable processes of this type are sometimes referred to in the art as "continuous liquid interface (or interphase) product (or printing)" ("CLIP") processes. Such methods are described, for example, in documents WO 2014/126830; WO 2014/126834; WO 2014/126837; and Tumbleston et al., "Continuous Liquid Interface Production of 3D Objects", Science Vol. 347, number 6228, p. 1349-1352 (March 20, 2015).

When stereolithography is conducted over an oxygen permeable building window, the production of an article using an actinic radiation curable composition in accordance with the present invention may be made possible in a CLIP procedure by creating an oxygen-containing "dead zone" which is a thin, uncured layer of the curable composition between the window and the surface of the cured article while it is being produced . In such a process, a composition curable by actinic radiation is used, and in this composition, the curing (polymerization) is inhibited by the presence of molecular oxygen; such inhibition is typically observed, for example, in curable compositions which are capable of being cured by free radical mechanisms. The thickness of the dead zone that is desired can be maintained by choosing various control parameters such as the photon flux and the optical and curing properties of the curable composition. The CLIP process works by projecting a continuous sequence of actinic radiation (e.g., UV) images (which may be generated by a digital light processing imaging unit, for example) through a permeable window to oxygen, transparent to actinic radiation (eg, UV) below a bath of the actinic radiation-curable composition maintained in liquid form. A liquid interface below the advancing (growing) item is maintained by the dead zone created below the window. The curing article is continuously pulled out of the bath of curable composition by actinic radiation above the dead zone, which can be replenished by feeding additional amounts of the curable composition into the bath to compensate for the amounts of curable composition by actinic radiation being hardened and incorporated into the growing article.

Exemplary aspects of the present invention may be summarized as follows:

Aspect 1: An actinic radiation curable composition comprising:
a) at least one polyamide which does not contain functional groups curable by actinic radiation; And
b) at least one compound curable by actinic radiation, the at least one compound curable by actinic radiation being a liquid at 25°C;
condition i), condition ii) or condition iii) being satisfied:
i) the at least one polyamide is an unmodified polyamide or a combination of unmodified polyamides and the at least one polyamide is completely dissolved in the composition curable by actinic radiation at 25° C.;
ii) at least a portion of the at least one polyamide is present as dispersed particles in the composition curable by actinic radiation at 25°C;
iii) the actinic radiation curable composition is a gel at 25°C and a liquid at 100°C or more.

Aspect 2: The actinic radiation curable composition according to Aspect 1, wherein the actinic radiation curable composition comprises up to 30 parts by weight of polyamide per 100 parts by weight of actinic radiation curable compound.

Aspect 3: The actinic radiation-curable composition according to Aspect 1 or Aspect 2, wherein the actinic radiation-curable composition comprises 0.5 to 25 parts by weight of polyamide per 100 parts by weight of actinic radiation-curable compound .

Aspect 4: The actinic radiation-curable composition according to any of Aspects 1 to 3, wherein the actinic radiation-curable composition is a homogeneous liquid at 25°C.

Aspect 5: The actinic radiation-curable composition according to any of Aspects 1 to 3, wherein condition iii) is satisfied.

Aspect 6: The actinic radiation-curable composition according to any of Aspects 1 to 3, wherein condition ii) is satisfied and particles of the at least one polyamide are dispersed in a liquid matrix of the at least one compound curable by actinic radiation.

Aspect 7: The actinic radiation curable composition according to any of Aspects 1 to 6, wherein the at least one actinic radiation curable compound comprises at least one actinic radiation curable compound selected from the group consisting of functionalized compounds by (meth)acrylate, cyanoacrylates, methylidene malonates, itaconates and combinations thereof.

Aspect 8: The actinic radiation curable composition according to any of Aspects 1 to 7, wherein the at least one actinic radiation curable compound comprises at least one (meth)acrylate functionalized oligomer.

Aspect 9: The actinic radiation curable composition according to any one of Aspects 1 to 8, wherein the at least one actinic radiation curable compound comprises at least one (meth)acrylate functionalized compound selected from the group consisting of monomeric (meth)acrylates, polyester (meth)acrylate oligomers, polyether (meth)acrylate oligomers, amine (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, (meth)acrylate oligomers urethane and combinations thereof.

Aspect 10: The actinic radiation-curable composition according to any one of Aspects 1 to 9, wherein the actinic radiation-curable composition has a viscosity at 25°C of not more than 100,000 mPa.s.

Aspect 11: The actinic radiation-curable composition according to any of Aspects 1 to 10, wherein the at least one polyamide comprises at least one polyamide which is a block copolymer composed of at least one polyamide block and at least one block selected from the group consisting of polyester blocks, polysiloxane blocks, polyether-ester blocks, polyether blocks, and polyorganosiloxane blocks.

Aspect 12: The actinic radiation curable composition according to any of Aspects 1 to 11, wherein the at least one polyamide comprises at least one polyamide which is a block copolymer composed of at least one polyamide block and at least one block selected from the group consisting of polyethylene glycol blocks, polypropylene glycol blocks, polytetramethylene glycol blocks, polydimethylsiloxane blocks, and ethoxylated bisphenol A blocks.

Aspect 13: The actinic radiation curable composition according to any of Aspects 1 to 12, wherein the at least one polyamide block is a polyamide block selected from the group consisting of a polyamide 6,6, a polyamide 6,10 , a polyamide 10,10, a polyamide 6,12, a polyamide 4,6, a polyamide 6, a polyamide 11 and a polyamide 12.

Aspect 14: The actinic radiation curable composition according to any of Aspects 1 to 13, wherein the at least one polyamide comprises at least one polyamide which is a thermoplastic elastomer and which is a block copolymer composed of at least a polyamide block chosen from the group consisting of a polyamide 6,6, a polyamide 6,10, a polyamide 10,10, a polyamide 6,12, a polyamide 4,6, a polyamide 6, a polyamide 11 and a polyamide 12 and at least one polytetramethylene glycol block.

Aspect 15: The actinic radiation curable composition according to any of Aspects 1 to 14, wherein the actinic radiation curable composition is capable of being cured by exposure to at least one of ultraviolet light, visible light, and electron beam radiation.

Aspect 16: The actinic radiation curable composition according to any of Aspects 1 to 15, wherein the at least one polyamide comprises at least one polyamide having a number average molecular weight ranging from 10,000 to 100,000 g/mole .

Aspect 17: The actinic radiation-curable composition according to any one of Aspects 1 to 16, the at least one polyamide comprises at least one polyamide selected from the group consisting of a polyamide 6,6, a polyamide 6,10, a polyamide 10,10, a polyamide 6,12, a polyamide 4,6, a polyamide 6, a polyamide 11 and a polyamide 12.

Aspect 18: The actinic radiation curable composition according to any of Aspects 1 to 17, further comprising at least one photoinitiator.

Aspect 19: The actinic radiation-curable composition according to any of Aspects 1 to 18, wherein the actinic radiation-curable composition comprises less than 0.1% by weight, based on the weight of the actinic radiation-curable composition , non-reactive solvent.

Aspect 20: The actinic radiation curable composition according to any of Aspects 1 to 19, wherein the actinic radiation curable composition is free of non-reactive solvent.

Aspect 21: The actinic radiation curable composition according to any of Aspects 1 to 20, wherein condition i) is satisfied and the actinic radiation curable composition further comprises an amount of at least one non-reactive solvent effective for completely dissolving the at least one polyamide in the composition curable by actinic radiation at 25°C.

Aspect 22: The actinic radiation curable composition according to any of Aspects 1 to 21, wherein the at least one polyamide is partially dissolved in the at least one actinic radiation curable compound at 25°C.

Aspect 23: The actinic radiation curable composition according to any of Aspects 1 to 22, wherein the at least one polyamide comprises at least one polyamide which is a thermoplastic.

Aspect 24: The actinic radiation curable composition according to any of Aspects 1 to 23, wherein the at least one polyamide comprises at least one polyamide which is a thermoplastic elastomer.

Aspect 25: The actinic radiation curable composition according to any of Aspects 1 to 24, wherein component a) and component b) have a Hansen solubility parameter δp of 7 to 10 MPa ^1/2 and a parameter of Hansen solubility δh from 4.5 to 8.5 MPa ^1/2 .

Aspect 26: The actinic radiation curable composition according to any of Aspects 1 to 25, wherein the actinic radiation curable composition is selected from the group consisting of adhesives, sealants, coatings, resins for three-dimensional printing and for additive manufacturing, inks and molding resins.

Aspect 27: A process for preparing a cured polymeric material, wherein the process comprises curing the actinic radiation curable composition according to any of Aspects 1 to 26 using actinic radiation.

Aspect 28: The method according to Aspect 27, wherein the method uses at least one of ultraviolet and visible light.

Aspect 29: A cured polymeric material obtained according to the process according to Aspect 27 or Aspect 28.

Aspect 30: The cured polymeric material according to Aspect 29, wherein the cured polymeric material has an energy at break, as measured by ASTM D256–10 (2018), higher than that of a cured polymeric material obtained by photocuring an analogous actinic radiation curable composition which has the same composition as the actinic radiation curable composition but which does not contain the at least one polyamide.

Aspect 31: A method of preparing a three-dimensional article by additive manufacturing, comprising using the actinic radiation-curable composition according to any of Aspects 1 to 26 to manufacture the three-dimensional article.

Aspect 32: The process according to Aspect 31, in which following an additive manufacturing step, the three-dimensional article is subjected to an additional step of post-curing using actinic radiation and/or heat.

Aspect 33: The process of either Aspect 31 or Aspect 32, in which following an additive manufacturing step, an actinic radiation cured polymer phase in the three-dimensional article is removed from the three-dimensional article at using thermal degradation and/or washing with an organic solvent.

Aspect 34: The method according to Aspect 33, wherein following the removal of the cured polymer phase by actinic radiation, a polyamide phase remains in the three-dimensional article and the polyamide phase is then subjected to a thermal sintering.

Aspect 35: A method of preparing a three-dimensional article, comprising:
a) applying a first coat of an actinic radiation curable composition according to any of Aspects 1 to 26 to a surface;
b) curing the first layer to obtain a first cured layer;
c) applying a second layer of the actinic radiation curable composition over the first cured layer;
d) curing the second layer to obtain a second hardened layer adhered to the first hardened layer;
e) repeating steps c) and d) a desired number of times to construct a three-dimensional article comprised of the actinic radiation curable composition in cured form.

Aspect 36: The process of Aspect 35, wherein the actinic radiation curable composition is heated above a melting point of a) the at least one polyamide which does not contain actinic radiation curable functional groups .

Aspect 37: A method of preparing a three-dimensionally printed article using digital light projection printing, stereolithography printing or multi-jet printing, comprising irradiating a actinic radiation curable composition according to any of Aspects 1 to 26, layer by layer to form the three-dimensionally printed article.

Aspect 38: A method of preparing a three-dimensional article, comprising:
a) heating an actinic radiation curable composition according to any of Aspects 1 to 26 to a temperature above a melting point of component a);
b) applying a first layer of the heated actinic radiation curable composition to a surface;
c) cooling the first layer to a temperature below the melting point of component a) to give a cooled first layer;
d) curing the cooled first layer to obtain a hardened first layer;
e) applying a second layer of the heated actinic radiation curable composition over the first cured layer;
f) cooling the second layer to a temperature below the melting point of component a) to give a cooled second layer;
g) curing the second layer to obtain a second hardened layer adhered to the first hardened layer;
h) repeating steps e), f) and g) a desired number of times to construct a three-dimensional article comprised of the actinic radiation-curable composition in cured form.

Aspect 39: The process of Aspect 38, in which steps c) and d) are carried out at the same time and steps f) and g) are carried out at the same time.

Aspect 40: A process for preparing an actinic radiation curable composition according to any of Aspects 1 to 26, wherein the process comprises combining the at least one polyamide, the at least one curable compound by actinic radiation, and at least one volatile solvent capable of solubilizing the at least one polyamide to obtain an initial mixture and the elimination of at least part of the volatile solvent from the initial mixture to obtain the composition curable by actinic radiation .

In this specification, embodiments have been described in a manner that permits writing a clear and concise description, but it is intended and it will be appreciated that embodiments may be combined or separated in various ways without move away from the invention. For example, it will be appreciated that all of the preferred features described herein are applicable to all aspects of the invention described herein.

In certain embodiments, the invention herein may be deemed to exclude any element or process step which does not significantly affect the basic and novel characteristics of the actinic radiation-curable compositions, processes for the preparation of the compositions radiation-curable compositions, methods for using the actinic radiation-curable compositions, and articles prepared from the actinic radiation-curable compositions. Additionally, in certain embodiments, the invention may be deemed to exclude any element or method step not specified herein.

Although the invention is illustrated and described herein by reference to specific embodiments, the invention is not intended to be limited to the details presented. Rather, various modifications may be made in detail within the scope and range of equivalents of the claims and without departing from the invention.

Examples

Example 1: Compatibility of polyamides not comprising functional groups curable by actinic radiation (PEBAX® of grades 2533 and 4023, Arkema) with mixtures of compounds curable by actinic radiation (SARTOMER® CN1964CG; SR210CG; SR506D, all from Arkema)

These materials are:
SARTOMER ^® PRO22456: 10% by weight of PEBAX® 2533 in SARTOMER® SR506D
SARTOMER ^® PRO22457: 10% by weight of PEBAX® 4023 in SARTOMER® SR506D
PRO22456 and PRO22457 were prepared by melting Pebax pellets at 110°C (for PEBAX® 2533) or 120°C (for PEBAX® 4023) in a melter. Then, the preheated SR506D monomer was added with stirring with 1000 ppm of MEHQ and under O ₂ .
SARTOMER ^® SR210CG: polyethylene glycol dimethacrylate (200) (PEG200DMA)
SARTOMER ^® SR506D: isobornyl acrylate (IBOA)

Tables 1 to 3 show the mixing conditions and the compatibility results of various combinations of polyamides with compounds curable by actinic radiation.

Table 1: Examples 1A to 1D EXAMPLE 1A 1B 1C (reference) 1D ^PEBAX® 2533 PRO22456 10 10 - - ^PEBAX® 4023 PRO22457 - - - 10 oligomer CN1964CG 30 50 50.4 50 monomer SR210CG 50 - - - SR506D - 40 49.5 40 Total 90 100 99.9 100 % of PEBAX in the formulation 1 1 0 1 Mixing process (manual, unless otherwise stated) Separately heated to 110°C then mixed together and heated for 5 minutes at 110°C Separately heated to 110°C then mixed together and heated for 30 minutes at 110°C then mixed every 5 minutes Mixed and heated to 110°C for 10 minutes Separately heated to 110°C then mixed together and heated for 30 minutes at 110°C then mixed every 5 minutes Immediately after mixing (hot) Liquid with small agglomerates Liquid with small agglomerates Liquid Liquid with small agglomerates After 30 minutes at 20-25°C Liquid with small agglomerates Liquid with small agglomerates Liquid Liquid with small agglomerates After 24 hours at 20-25°C gelled Liquid with small agglomerates Liquid gelled

Table 2: Examples 1E to 1H EXAMPLE 1E 1F 1G 1 hour ^PEBAX® 2533 PRO22456 20 35 50 15 ^PEBAX® 4023 PRO22457 - - - - oligomer CN1964CG 30 30 30 30 monomer SR210CG - - - - SR506D 50 35 20 55 Total 100 100 100 100 % of PEBAX in the formulation 2 3.5 5 1.5 Mixing process (manual, unless otherwise stated) Mixed for 20 minutes at 75°C and 800 rpm with Dispermill Discovery 200, then heated at 110°C for 15 minutes Immediately after mixing (hot) Lumpy Lumpy Lumpy Liquid with some lumps After 30 minutes at 20-25°C Liquid Started to gel gelled Liquid After 24 hours at 20-25°C gelled gelled gelled gelled

Table 3: Examples 1I to 1K EXAMPLE 1I 1D 1K ^PEBAX®
(10%) PRO22456 20 30 50 PRO22457 - - - oligomer CN1964CG - - - monomer SR210CG - - - SR506D 80 70 50 Total 100 100 100 % of PEBAX Mixing process (manual, unless otherwise stated) Separately heated to 110°C then mixed together and heated for 30 minutes at 110°C then mixed every 5 minutes Immediately after mixing (hot) Liquid Liquid Liquid After 30 minutes at 20-25°C Liquid with small agglomerates Started to gel Started to gel After 24 hours at 20-25°C gelled gelled gelled

The above results show that adding the polyamides to the actinic radiation-curable compounds generally provided a liquid, or a liquid with small agglomerates immediately after mixing, when hot. However, the mixtures almost always produced a homogeneous gel after cooling for 24 hours at room temperature. Either of these forms should be suitable for use as a material for additive manufacturing.

Example 2: Properties of cured formulations:

This example is based on the dispersion of a PEBAX powder in mixtures of oligomers or monomers. Four different formulations were prepared by combining a polyamide powder that does not contain an actinic radiation curable functional group with four different actinic radiation curable compounds. All preparation and testing was done at room temperature and is detailed below.

Mixing was done using a Glass-Col Rugged Rotator. The samples were cured in silicone molds under an LED Conveyor at maximum intensity, 395 nm wavelength, 50 rpm, and two passes were made for each sample.

The test was performed as follows:
Viscosity was measured before curing using a Brookfield cone and plate rheometer. Cured tensile properties were measured using an Instron according to the procedures of ASTM D638.
The results and properties after curing are shown in Table 4, with the exception of viscosity, which was measured on the blends before curing.

Table 4: Example 2 formulations and properties after curing Amount of polyamide*, % by weight Actinic radiation curable compound: N3xtDimension ^® P-121 Viscosity (mPa.s)
before curing Tensile strength (MPa) Elongation (%) Modulus (MPa) Energy at break (kg.m ² .s ^-2 ) state of the polyamide 0% 50 47.1 7.8 900 0.144 1% 47.4 21.4 3.3 699.6 0.186 Dispersion 3% 49.2 20.1 3.3 649.8 0.185 Dispersion 5% 57.6 21.3 4 584.3 0.235 Dispersion Actinic radiation curable compound: N3xtDimension ^® I-150 0% 46000 15.8 50 172.4 1.68 - 1% 49225 19.2 36.6 243.3 3,112 Dissolution 3% 12071 14.55 34.75 177.65 2.0655 Dissolution 5% 6522 17.7 22.3 246.2 1,627 Dissolution 10% 9121 12.9 31.6 149.1 1.94 Blend Actinic radiation curable compound: N3xtDimension ^® P-220 0% 1425 36.1 4.9 990.5 0.1 - 10% 2009 16.9 3.9 486.2 0.219 - 20% 4920 16.6 4.1 466.1 0.206 - Actinic radiation curable compound: N3xtDimension ^® F-230 0% 550 12.6 39.9 162.6 0.8 - 10% 566 10.4 29.6 146.5 1,506 Dispersion 20% 944 14.1 18.6 214 1,123 Dispersion

*PEBAX® 9002 from Arkema

These results show that the fracture energy was improved (it was higher than the reference) for all the samples incorporating the polyamide. Generally, all samples incorporating the polyamide show an increase in opacity. Improved viscosity (below benchmark) before cure was observed in blends of polyamide with the actinic radiation-curable compounds P–220 and I–150.

Example 3: Properties of 4-tert-butylcyclohexyl acrylate with 17% by weight polyamide compared to 100% 4-tert-butylcyclohexyl acrylate

Samples were prepared by first mixing 4-tert-butylcyclohexyl acrylate (TBCHA) (SARTOMER® SR217, Arkema) with 17% polyamide (PEBAX® 2533, Arkema). The first step consisted in melting the Pebax pellets at 110°C or 120°C in a melter then adding the preheated SR217 monomer with stirring with 1,000 ppm of MEHQ and under O ₂ in a second step. This preparation was mixed together at 110°C with 4% by weight of a photopolymerization initiator (Irgacure® TPO-L, BASF). These were compared to pure 4–tert-butylcyclohexyl acrylate, also in combination with 4% by weight of the same photopolymerization initiator. The samples were cured under a Conveyor LED at maximum intensity, at a wavelength of 395 nm and 5 passes on each side at 5 m/min were made for each sample. When they were post-cured, this was done in an oven for 2 hours at 120°C. Their properties were compared using dynamic mechanical analysis (DMA) as well as a three-point bend test. A cured sample of the blend of 4–tert-butylcyclohexyl acrylate with 17% polyamide was also post-cured with heat and its properties were measured by AMD and a three-point bend test. The results are shown in Table 5.

Table 5: Results of Example 3 Example 3A 3B 3C (reference) Polyamide, wt% in TBCHA 17 17 0 Treatment Photocure only Light-curing and post-curing Photocure only AMD – twist Tα (i.e. the highest transition temperature) °C -40/-8 -40/-3 31 E’ at 200°C Flow above 40°C Flow above 40°C Flow/slip above 40°C Three-point bend test (2mm/min) Breaking stress, MPa 9.6 7.3 17 standard deviation 1.0 0.9 4 Breaking deflection (mm) 4.8 5.8 4.9 standard deviation 0.9 1.1 1.1 Flexural Modulus (GPa) 363 415 1337 standard deviation 30 37 99

Claims (15)

A composition curable by actinic radiation comprising:
a) at least one polyamide which does not contain functional groups curable by actinic radiation; And
b) at least one compound curable by actinic radiation, the at least one compound curable by actinic radiation being a liquid at 25°C;
condition i), condition ii) or condition iii) being satisfied:
i) the at least one polyamide is an unmodified polyamide or a combination of unmodified polyamides and the at least one polyamide is completely dissolved in the composition curable by actinic radiation at 25° C.;
ii) at least a portion of the at least one polyamide is present as dispersed particles in the composition curable by actinic radiation at 25°C;
iii) the actinic radiation curable composition is a gel at 25°C and a liquid at 100°C or more. The actinic radiation curable composition of claim 1, wherein the actinic radiation curable composition comprises up to 30 parts, preferably 0.5 to 25 parts, by weight of polyamide per 100 parts by weight of actinic radiation curable compound. An actinic radiation-curable composition according to claim 1 or 2, wherein condition iii) is satisfied. An actinic radiation-curable composition according to claim 1 or 2, wherein condition ii) is satisfied and particles of the at least one polyamide are dispersed in a liquid matrix of the at least one actinic radiation-curable compound. The actinic radiation curable composition according to any one of claims 1 to 4, wherein the at least one actinic radiation curable compound comprises at least one actinic radiation curable compound selected from the group consisting of compounds functionalized with (meth) acrylate, cyanoacrylates, methylidene malonates, itaconates and combinations thereof, preferably at least one (meth)acrylate functionalized oligomer. The actinic radiation curable composition according to any one of claims 1 to 5, wherein the at least one polyamide comprises at least one polyamide which is a block copolymer composed of at least one polyamide block and at least one selected from the group consisting of polyester blocks, polysiloxane blocks, polyether-ester blocks, polyether blocks, and polyorganosiloxane blocks. An actinic radiation curable composition according to any one of claims 1 to 6, wherein the at least one polyamide comprises at least one polyamide which is a block copolymer composed of at least one polyamide block and at least one selected from the group consisting of polyethylene glycol blocks, polypropylene glycol blocks, polytetramethylene glycol blocks, polydimethylsiloxane blocks, and ethoxylated bisphenol A blocks. An actinic radiation curable composition according to any one of claims 1 to 7, wherein the at least one polyamide comprises at least one polyamide selected from the group consisting of polyamide 6,6, polyamide 6,10, polyamide 10 ,10, a polyamide 6,12, a polyamide 4,6, a polyamide 6, a polyamide 11 and a polyamide 12. An actinic radiation-curable composition according to any one of claims 1 to 8, wherein the actinic radiation-curable composition comprises less than 0.1% by weight, based on the weight of the actinic radiation-curable composition, of solvent not reactive and preferably being free of non-reactive solvent. An actinic radiation-curable composition according to any one of claims 1 to 9, wherein the at least one polyamide is partially dissolved in the at least one actinic radiation-curable compound at 25°C. A process for preparing a cured polymeric material, wherein the process comprises curing the actinic radiation curable composition according to any one of claims 1 to 10 using actinic radiation. Cured polymeric material obtained by the process according to claim 11. Cured polymeric material according to claim 12, wherein the cured polymeric material exhibits an energy at break, as measured by ASTM D256-10 (2018), higher than that of a cured polymeric material obtained by photocuring of an analogous actinic radiation curable composition which has the same composition as the actinic radiation curable composition but does not contain the at least one polyamide. A method of preparing a three-dimensional article by additive manufacturing, comprising using the actinic radiation-curable composition according to any one of claims 1 to 10 to manufacture the three-dimensional article. A method according to claim 14, wherein, following an additive manufacturing step, the three-dimensional article is subjected to an additional step of post-curing using actinic radiation and/or heat.