RU2631794C1 - Polymeric three-dimensional object of complex shape and method of manufacturing polymeric three-dimensional object of complex shape - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: polymeric three-dimensional object of complex shape is made up of layers of height h successively formed from a liquid photopolymer cured point-wise under the influence of light radiation and attached to each other during the formation process. Herewith the size of the curing "point" preferably coincides with the size of the light beam spot initiating the curing of the photopolymerizable composition. In addition, the three-dimensional object has in the entire volume a system of randomly located open bonded pores, each with a maximum transverse linear dimensionρ less than the height of the layer h and the diameter of the "point" d. The method of manufacturing a polymeric three-dimensional object of complex shape with a system of open bonded pores made up of layers obtained by successive curing each layer of a photopolymerizable composition by successive moving a light beam along it initiating its photocuring. As a photopolymerizable composition, a mixture of a photopolymer with a non-polymerizable component (an organic solvent, for example, methanol or 1-butanol or dinonyl phthalic acid or a mixture thereof) is used, with the possibility of heterophasic stratification of the composition during its photocuring and self-formation of the porous polymer structure with the pore size ρ= (Dτ)^0.5, where D is the diffusion coefficient of the composition,τ curing time of the "point". Herewith the speed V of moving the light beam is given by the condition: d/τ> V>ρ/τ. After completion of the irradiation, the non-polymerization component is removed from the volume of randomly located openly bonded pores of the formed object of complex shape, preferably washed in an organic solvent, followed by its removal by evaporation.

EFFECT: accelerating the process of manufacturing a three-dimensional polymer object and improving its quality.

4 cl, 2 dwg

Description

The invention relates to the field of manufacture of physical form carriers according to a geometric or mathematical model, in particular to the manufacture of three-dimensional objects of complex shape from a curing liquid under the influence of radiation by successively building up layers, and can be used to make models of machine parts, mechanisms, architectural, geodetic and other models, mannequins, anatomical models, forming elements of molds and dies, foundry molds, cliches, similar objects in medical , Electronics, automotive, aerospace, art, etc., as well as critical parts of devices with desired physical properties.

At present, three-dimensional objects of complex shape that have a porous structure are becoming increasingly relevant. Most effectively, such objects can be obtained using additive technologies and, in particular, by the method of stereolithography. So, in [3D fiber deposition and stereolithography techniques for the design of multifunctional nanocomposite magnetic scaffolds. Roberto De Santis, Ugo D'Amora, Teresa Russo, Alfredo Ronca, Antonio Gloria, Luigi Ambrosio. J Mater Sci: Mater Med (2015) 26: 250] porous polymer objects were prepared using standard SLA technology. The photopolymerizable composition was a mixture of polyethylene glycol diacrylate / Fe ₃ O ₄ nanoparticles (90/10). The periodic structure was set by a CAD file. Received porous cylinders 6 × 8 mm with a pore size of 500 μm. The disadvantage of this method is that each pore was outlined by a laser beam and, accordingly, could not be less than the size of the light spot of the polymerizing laser.

As a prototype, a polymer three-dimensional object of complex shape was selected [RF patent No. 2145924, IPC ⁷ B29D 9/00, B29C 41/22, B32B 1/00, B32B 1/10, publ. 02/27/2000], composed of layers successively formed from a liquid photopolymer cured by radiation and attached to each other during formation, while layers of thickness h are non-planar, continuously transitioning into each other, the base of the layers consist of a final the number N _{m of} "points" of linear size L _m , the position of the center of any "point" of the object along the Z coordinate is described by the equation

where Z _{n, m} is the Z coordinate of the "point" n of the layer m;

m - layer number, m = 1, 2, 3, etc .;

h is the thickness of the layer;

n _m - the number of "points" according to the sequence of construction of the layer m;

N _m - the sum of the "points" of the layer m.

The term "point" refers to the spot area of a light beam initiating the curing of the photopolymer.

The well-known polymer three-dimensional object is characterized by manufacturing accuracy and increased strength. At the same time, the known invention did not have the task of giving the polymer three-dimensional object additional properties, in particular sorption, filtering, exchange, separation properties, as well as optimization by weight of the finished product, etc.

Thus, the object of the present invention was to expand the functionality of polymer three-dimensional objects composed of layers successively formed from a liquid photopolymer cured by radiation.

This problem is solved by a polymeric three-dimensional object of complex shape, composed of layers of height h, successively formed from a liquid photopolymer curing pointwise under the influence of light radiation, and attached to one another during the formation process, while the size of the curing “point” mainly coincides with the size of the light spot a beam initiating the curing of the photopolymerizable composition. According to the proposal, a polymer three-dimensional object of complex shape in its entirety has a system of randomly located open connected pores, each with a maximum transverse linear dimension ρ less than the layer height h and the diameter of the “point” d.

The claimed polymer three-dimensional object is made by sequential curing of each layer of a photopolymerizable composition by successive movement of a light beam along it, initiating its photocure, while a mixture of a photopolymer with a non-polymerization component (NC) is used as a photopolymerizable composition, with the possibility of heterophasic separation of the composition during its photo-curing a porous polymer structure with a pore size ρ = (Dτ) ^0.5 , where D is the coefficient nt diffusion of the composition, τ is the curing time of the “point”. The speed V of the movement of the light beam along the polymerizing layer is set from the condition: d / τ>V> ρ / τ. After the completion of irradiation, the non-polymerization component is removed from the volume of randomly located open connected pores of the formed object of complex shape, in particular, it is washed in an organic solvent, followed by its removal by evaporation.

As a non-polymerization component, it is advisable to use an organic solvent, for example methanol, or 1-butanol, or phthalic acid dinonyl ether, or a mixture thereof. The use of an organic solvent is known for a one-stage production of a porous material with a hydrophobic pore surface [RF patent No. 2537860, IPC B01J 20/26, B82B 3/00, C08F 2/48, C08F 2/06, C08F 20/10, publ. 07/20/2014]. At the same time, the use of a non-polymerization component in the layer-by-layer fabrication of an object is characterized by at least one non-obvious feature, namely, the speed of movement of the photocurable beam. The meaning of the formula d / τ> V> ρ / τ is as follows. The fulfillment of the condition on the left side of the inequality is necessary for guaranteed polymerization of the photopolymerizable composition in the region of local exposure of the composition to the beam. If this condition is not fulfilled, then polymerization in the flare region does not lead to the formation of a solid phase of the polymer and, accordingly, there will be not only heterophase separation necessary for self-formation of the porous structure, but also, in general, the formation of a stable 3-dimensional object. The fulfillment of the right-hand side of the inequality provides the mode of non-crowding out the ND from the region of beam illumination. Accordingly, this provides a predetermined and constant concentration of nanocrystals in the polymerization region, which is also necessary for heterophasic separation of the polymerizable medium and the formation of the porous structure of a 3-dimensional object.

The claimed technical solutions are illustrated by examples of implementation. Examples are given for two types of objects.

The first. An object of arbitrary shape, composed of M flat layers of height h, containing randomly located open pores between the layers of size ρ smaller than h, formed from a liquid photopolymer under the influence of initiating radiation and attached to one another during the formation of the object. Each layer consists of a finite number N _{m of} “points”, the transverse dimension of which d is determined by the resolution of the optical beam focusing device, and contains a system of randomly located open and interconnected pores with a size ρ smaller than d. The center position of any "point" of the object along the Z coordinate is described by the equation:

where Z _{n, m} is the Z coordinate of the "point" n of the layer m;

m is the layer number; m = 1, 2, 3, etc.

h is the thickness of the layer;

n _m - the number of "points" according to the sequence of construction of the layer m;

N _m - the sum of the "points" of the layer m.

This object contains in its entirety a system of randomly located open connected pores, each with a maximum transverse linear dimension ρ less than the layer height h and the diameter of the “point” d.

Second. An object of arbitrary shape, composed of M nonplanar, transitioning into each other layers of height h, containing randomly located open pores between the layers of size ρ smaller than h, formed from a liquid photopolymer under the influence of initiating radiation and attached to each other during the formation of the object. Each non-planar layer consists of a finite number N _{m of} “points”, the transverse dimension of which d is determined by the resolution of the optical beam focusing device, and contains a system of randomly located open and interconnected pores of size ρ smaller than d. The center position of any "point" of the object along the Z coordinate is described by the equation:

where Z _{n, m} is the Z coordinate of the "point" n of the layer m;

m is the layer number; m = 1, 2, 3, etc.

h is the thickness of the layer;

n _m - the number of "points" according to the sequence of construction of the layer m;

N _m - the sum of the "points" of the layer m.

This object contains in its entirety a system of randomly located open connected pores, each with a maximum transverse linear dimension ρ less than the layer height h and the diameter of the “point” d.

For clarity, explanatory drawings are provided.

In FIG. Figure 1 shows the order of position of the “points” of a three-dimensional polymer object of complex shape with a system of randomly located open connected pores composed of flat layers. In FIG. Figure 2 shows the order of position of the “points” of a three-dimensional polymer object of complex shape with a system of randomly located open connected pores composed of non-planar layers.

Example 1

A photopolymerizable composition was prepared by mixing 6 g of oligoester acrylate, which was used as α, ω-bis- (methacryloyloxyethylene-hydroxycarbonyloxy) ethyleneoxyethylene (commercial grade OKM-2), 0.06 g of photoinitiator, which was used dimethoxyphenylacetophenone, and 4 g of non-polymerization as which was used phthalic acid dinonyl ether. The finished composition was placed in a reactor equipped with a system for vertical movement of the substrate. An object of complex shape was grown by moving the substrate down by immersing the forming object in the volume of the composition. To form the first layer, the substrate was positioned so that between its surface and the composition surface there was a composition layer equal to 100 μm. Then, the surface of the composition was irradiated using a scanner with a beam of initiating radiation, for example, radiation from a He-Cd UV laser with a power of 10 mW with a beam diameter d = 100 μm. With a corresponding luminous flux of 1 W / mm ² , the curing time of a composition point with a size of d = 100 μm is 0.01 s. When the diffusion coefficient of the composition is D = 50 μm ² / s, the size of the self-forming pores is ρ = (Dτ) ^0.5 = 0.7 μm. In this case, the speed of movement of the light spot must satisfy the condition: 10 mm / s = d / τ>V> ρ / τ = 0.07 mm / s. The value V = 8 mm / s was used. After irradiation of the 1st layer, the substrate was lowered into the bulk of the composition to flow the composition onto the surface of the formed layer, then raised so that the composition layer above the previously formed polymer layer was 100 μm. The formation of the second and subsequent layers was also carried out with the scanning speed of the light beam V = 8 mm / s. After completion of the optical formation, the object was separated from the substrate, washed with isopropyl alcohol, and then the solvent was removed by vacuum. The average pore size on the cleaved object, determined by atomic force microscopy, was 0.7 μm. The presence of pore openness was controlled by placing the base of the obtained porous three-dimensional object in an immersion medium — toluene, which has a refractive index close to the polymer. As a result, the object became completely transparent. This indicates that the pores in the resulting multilayer object are interconnected throughout the volume.

Example 2

A photopolymerizable composition was prepared by mixing 6 g of oligoester acrylate, which was used as α, ω-bis- (methacryloyloxyethylene-hydroxycarbonyloxy) ethyleneoxyethylene (industrial grade OKM-2), photoinitiator, which was used as a mixture of 0.01 g of 3,6-di-tert -butyl-4-fluoro-benzoquinone-1.2 and 0.1 g of triethylamine, and 4 g of a non-polymerization-capable component, which was used methanol. The finished composition was placed in a reactor with a transparent bottom, for example, of silicate glass, on the surface of which a release layer was applied, for example, perfluorinated liquid RZHN. The substrate on which the object was grown was lowered into a photopolymerizable composition until a composition layer 100 μm thick was formed. Next, the composition was irradiated using a scanner with a beam of initiating radiation, for example, radiation from a 20 mW He-Ne laser with a beam diameter d = 100 μm. With an appropriate luminous flux of 2 W / mm ² , the curing time of a composition point with a size of d = 100 μm is 0.01 s. When the diffusion coefficient of the composition is D = 100 μm ² / s, the size of the self-forming pores is ρ = (Dτ) ^0.5 = 1 μm. In this case, the speed of movement of the light spot must satisfy the condition: 10 mm / s = d / τ>V> ρ / τ = 0.1 mm / s. The value V = 5 mm / s was used. After irradiation of the first plane layer, the composition volume equal to the volume of the composition cured in the first layer was added to the reactor, and the substrate was raised to the height of the partition layer of the model of a three-dimensional object of complex shape in height. The formation of the second and subsequent layers was also carried out with a scanning speed of the light beam V = 5 mm / s. After completion of the optical formation, the object was separated from the substrate, washed with isopropyl alcohol, and then the solvent was removed by vacuum. The average pore size on the cleaved object, determined by atomic force microscopy, was 1 μm. The presence of pore openness was controlled by placing the base of the obtained porous three-dimensional object in an immersion medium — toluene, which has a refractive index close to the polymer. As a result, the object became completely transparent. This indicates that the pores in the resulting multilayer object are interconnected throughout the volume.

Example 3

A photopolymerizable composition was prepared by mixing 6 g of oligoester acrylate, which was used as α, ω-bis- (methacryloyloxyethylene-hydroxycarbonyloxy) ethyleneoxyethylene (industrial grade OKM-2), a photoinitiator, which was used as a mixture of 0.015 g of 3,6-di-tert-butyl -4-fluoro-benzoquinone-1.2 and 0.1 g of triethylamine, and 4 g of a non-polymerization-capable component, which was used 1-butanol. The finished composition was placed in a reactor with a transparent bottom, for example, of silicate glass, on the surface of which a release layer was applied, for example, perfluorinated liquid RZHN. The substrate on which the object was grown was lowered into a photopolymerizable composition until a composition layer 100 μm thick was formed. Next, the composition was irradiated using a scanner with a beam of initiating radiation, for example, radiation from a 20 mW He-Ne laser with a beam diameter d = 100 μm. With an appropriate luminous flux of 2 W / mm ² , the curing time of a composition point with a size of d = 100 μm is 0.02 s. When the diffusion coefficient of the composition is D = 80 μm ² / s, the size of the self-forming pores is ρ = (Dτ) ^0.5 = 1.3 μm. In this case, the speed of movement of the light spot must satisfy the condition: 5 mm / s = d / τ>V> ρ / τ = 0.065 mm / s. The value V = 4 mm / s was used. Simultaneously with the transverse movement of the light spot, the substrate was raised along the Z coordinate according to the law:

where Z _{n, m} is the Z coordinate of the "point" n of the layer m;

m is the layer number; m = 1, 2, 3, etc.

h is the thickness of the layer;

n _m - the number of "points" according to the sequence of construction of the layer m;

N _m - the sum of the "points" of the layer m.

In accordance with this, an object of complex shape was formed with spiral layers in which the final longitudinal coordinate of the last point of the layer coincided with the beginning of the longitudinal coordinate of the first point of the next layer. Accordingly, there was no need for a separate procedure for the longitudinal movement of the object between the operations of forming layers. Topping up the photopolymerizable composition was carried out continuously as the points of the object were formed by the scanning beam. After completion of the optical formation, the object was separated from the substrate, washed with isopropyl alcohol, and then the solvent was removed by vacuum. The average pore size on the cleaved object, determined by atomic force microscopy, was 1.3 μm. The presence of pore openness was controlled by placing the base of the obtained porous three-dimensional object in an immersion medium — toluene, which has a refractive index close to the polymer. As a result, the object became completely transparent. This indicates that the pores in the resulting multilayer object are interconnected throughout the volume.

Claims (6)

1. A three-dimensional polymer object of complex shape, composed of layers of height h, sequentially formed from a liquid photopolymer curing pointwise under the influence of light radiation, and attached to one another during the formation process, while the size of the curing “point” mainly coincides with the size of the light beam spot initiating the curing of the photopolymerizable composition, characterized in that it has in its entirety a system of randomly located open connected pores, each with a maximum ρ echnym linear dimension smaller than the height h and diameter layer "points» d. 2. A method of manufacturing a polymeric three-dimensional object of complex shape with an open bonded pore system composed of layers obtained by sequentially curing each layer of a photopolymerizable composition by successively moving a light beam along it, initiating its photo-curing, characterized in that a mixture of a photopolymer with non-polymerization is used as a photopolymerizable composition component, with the possibility of heterophasic separation of the composition during its photocuring, while Height V moving the light beam along the polymerizable layer is set from the condition: dτ> V> ρ / τ, where τ is the curing time of the “point”, after completion of irradiation, the non-polymerization-capable component is removed from the volume of randomly located open connected pores of the formed object of complex shape. 3. The method according to p. 2, characterized in that as a non-polymerization component, an organic solvent, for example methanol, or 1-butanol, or phthalic acid dinonyl ether, or a mixture thereof is selected. 4. The method according to p. 2 or 3, characterized in that to remove the non-polymerization component from the volume of randomly located open connected pores, the object after irradiation is washed in an organic solvent, followed by its removal by evaporation.

Images