TW202124589A - Selective laser sintering composition and selective laser sintering 3d printing method employing the same - Google Patents

Abstract

A selective laser sintering composition and a selective laser sintering 3D printing method employing the same are provided. The selective laser sintering composition includes a nanoscale inorganic powder and a thermoplastic vulcanizate powder. The nanoscale inorganic powder has a D90 value in a range of1nm to 950nm, and the thermoplastic vulcanizate powder has a D90 value in a range of 40µm to 100µm. The difference (ΔT) between the onset temperature of melting (T_M onset) of the thermoplastic vulcanizate powder and the onset temperature of crystallization (T_C onset) of the thermoplastic vulcanizate powder is greater than or equal to 10℃. The thermoplastic vulcanizate powder includes a thermoplastic and a crosslinked polymer. The difference (ΔT) between the onset temperature of melting (T_M onset) of the thermoplastic and the onset temperature of crystallization (T_C onset) of the thermoplastic is greater than or equal to 10℃, and the weight ratio of the thermoplastic to the crosslinked polymer is from 1:1 to 1:4.

Description

Selective laser sintering composition and selective laser sintering three-dimensional printing method using the same

The present disclosure relates to a selective laser sintering composition and a method of using the composition to perform selective laser sintering three-dimensional printing.

Additive Manufacturing (commonly known as three-dimensional (3D) printing technology) is characterized in that it does not require molds to manufacture parts. Currently, additive manufacturing methods include fused deposition modeling (FDM), stereolithography (SLA), and selective laser sintering (SLS).

Fused deposition modeling (FDM) has the advantages of low price and simple technology. However, due to the limitations of the technology itself, it generally has disadvantages such as slow molding, limited size of molded objects, and poor precision. Stereo lithography (SLA) requires liquid plastic resin, photopolymer, and then cured by ultraviolet (UV) laser. SLA is considered to be a slower additive manufacturing method because small parts may take several hours or even days to complete.

Selective laser sintering (SLS) uses high-energy pulsed lasers to form parts layer by layer. First, a thin layer of material powder is provided in a chamber and is locally melted by means of a laser beam. After melting and subsequent solidification, the chamber can be lowered and a new layer of powder applied, and the construction process described above repeated. Therefore, it is possible to produce desired parts by repeatedly applying new layers and selective melting layer by layer.

A particularly important factor in selective laser sintering is the sintering window of the material powder used for sintering. The sinterable window of the material powder should be as wide as possible to reduce the warpage of the parts during the laser sintering operation. Rigid polyamide (PA) and polyetheretherketone (PEEK) are the more commonly used materials in SLS technology. Common soft materials include thermoplastic polyester elastomer (TPEE), thermoplastic polyurethane (TPU) and thermoplastic polyamide elastomer (TPAE) and other elastomers. However, traditional elastomers often exhibit a relatively wide melting temperature range during melt processing. During cooling, the crystallization rate is too fast, causing the material to cool and crystallize while still part of the molten state, which makes the SLS process more difficult. The narrow process window affects the sinterability of the material and the printing quality.

Therefore, the industry needs a novel material powder that can be used for laser sintering to improve sinterability and printing quality.

According to an embodiment of the present disclosure, the present disclosure provides a selective laser sintering composition. The selective laser sintering composition includes a nano-inorganic powder and a thermoplastic vulcanizate (TPV) powder. The value of the particle size distribution D90 of the inorganic powder is 1 nm to 950 nm, and the value of the particle size distribution D90 of the thermoplastic vulcanized elastomer powder is 40 μm to 100 μm. The difference (ΔT) between the onset temperature of melting (T _M onset) and the onset temperature of crystallization (T _C onset) of the thermoplastic vulcanized elastomer powder is greater than or equal to 10 ℃. The thermoplastic vulcanized elastomer powder includes a thermoplastic and a crosslinked polymer. The difference (ΔT) between the melting initiation temperature and the crystallization initiation temperature of the thermoplastic is greater than or equal to 10° C., and the weight ratio of the thermoplastic to the cross-linked polymer is 1:1 to 1:4. The crosslinked polymer is a crosslinked rubber, a crosslinked thermoplastic elastomer, or a combination thereof.

According to the embodiment of the present disclosure, the weight ratio of the inorganic nano powder to the thermoplastic vulcanized elastomer powder may be 0.2:99.8 to 0.8:99.2.

According to the embodiment of the present disclosure, the Shore A hardness of the thermoplastic vulcanized elastomer powder may be 50A to 98A.

According to an embodiment of the present disclosure, the nano-inorganic powder can be silicon oxide, aluminum oxide, titanium oxide, calcium carbonate, magnesium silicate, zinc oxide, magnesium oxide, or a combination of the foregoing.

According to the disclosed embodiment, the thermoplastic plastic is polypropylene, polyethylene, polyurethane, polyethylene terephthalate, polyamine, or any of the above combination.

According to the embodiment of the present disclosure, the cross-linked polymer may be a product obtained by cross-linking a rubber (or/and a thermoplastic elastomer) in the presence of a cross-linking agent and a plasticizer.

According to the disclosed embodiment, the rubber may be ethylene-propylene-diene monomer rubber, natural rubber (NR), polybutadiene rubber (BR), nitrile rubber ( nitrile butadiene rubber (NBR), styrene-butadiene rubber (SBR), acrylic rubber (ACM), ethylene-propylene rubber (EPR), EPDM rubber ( ethylene-propylene-diene monomer rubber, EPDM), or the above composition.

According to embodiments of the present disclosure, the crosslinking agent can be peroxide, phenolic resin, sulfur, sulfide, carbodiimide compound, aliphatic diamine, or a combination of the foregoing.

According to an embodiment of the present disclosure, the plasticizer is silicone oil, mineral oil, paraffin oil, or a combination of the above.

According to the embodiment of the present disclosure, the selective laser sintering composition may further include an additive, wherein the additive is a dye, a pigment, an antioxidant, a stabilizer, or the above composition. According to an embodiment of the present disclosure, the present disclosure provides a selective laser sintering three-dimensional printing method. The method includes the following steps: (A) forming a film layer, wherein the film layer includes the above-mentioned selective laser sintering composition; (B) scanning the film layer with a laser beam selectively irradiating the film layer to cure the selective laser Sintering the composition to form a part of an object; and (C) repeat steps (A) and (B) until the object is formed.

The following is a detailed description of the selective laser sintering composition of the present disclosure. It should be understood that the following description provides many different embodiments or examples for implementing different aspects of the present disclosure. The specific elements and arrangements described below are only a brief description of the present disclosure. Of course, these are merely examples and not the limitation of this disclosure. In addition, repeated reference numerals or labels may be used in different embodiments. These repetitions are only to briefly and clearly describe the present disclosure, and do not represent any connection between the different embodiments and/or structures discussed.

According to an embodiment of the present disclosure, the present disclosure provides a selective laser sintering composition. The selective laser sintering composition includes a nano-inorganic powder and a thermoplastic vulcanization elastomer powder, wherein the particle size distribution D90 of the thermoplastic vulcanization elastomer powder is 40 µm to 100 µm, and the thermoplastic vulcanization elastomer powder is melted The difference (ΔT) between the onset temperature of melting (T _M onset) and the onset temperature of crystallization (T _C onset) is greater than or equal to 10°C. By adding the specific thermoplastic vulcanized elastomer powder, the selective laser sintering composition of the present disclosure can be three-dimensionally printed by selective laser sintering to have elasticity and the same thermal properties as rigid plastics. Therefore, the present disclosure provides an elastic material that can be used for laser sintering, and solves the problem that traditional elastic materials are difficult to perform laser sintering due to the narrow sintering window.

In addition, the thermoplastic vulcanized elastomer powder used in the present disclosure contains thermoplastic as a continuous phase, and a cross-linked polymer (including a cross-linked rubber, a cross-linked thermoplastic elastomer, or a combination thereof) as a dispersed phase. Therefore, the melting behavior of the selective laser sintering composition of the present disclosure during laser sintering processing is exhibited by thermoplastics, and has a relatively obvious and wide sintering window. When cooled, the sintered product exhibits softness and elastic recovery deformation characteristics due to the rubber dispersed phase.

According to an embodiment of the present disclosure, the present disclosure provides a selective laser sintering composition. According to an embodiment of the present disclosure, the selective laser sintering composition includes a nano-inorganic powder and a thermoplastic vulcanizate (TPV) powder. According to an embodiment of the present disclosure, the value of the particle size distribution D90 of the inorganic powder can be about 1nm to 950nm, for example, about 1nm, 5nm, 10nm, 20nm, 50nm, 100nm, 150nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, or 950nm. If the value of the particle size distribution D90 of the inorganic powder is too high, the resulting selective laser sintering composition will have poor fluidity, and a uniform thickness cannot be obtained when automatic powder spreading equipment is used for powder bed spreading.的膜层。 The film layer. According to the embodiment of the present disclosure, the value of the particle size distribution D90 of the thermoplastic vulcanized elastomer powder may be about 40 µm to 100 µm, for example, about 40 µm, 50 µm, 60 µm, 70 µm, 80 µm, 90 µm, or 100 µm. If the value of the particle size distribution D90 of the thermoplastic vulcanization elastomer powder is too low, the thermoplastic vulcanization elastomer powder is likely to agglomerate due to static electricity, resulting in the difficulty of uniformly dispersing the thermoplastic vulcanization elastomer powder in the film layer. If the value of the particle size distribution D90 of the thermoplastic vulcanization elastomer powder is too high, the accuracy of the three-dimensionally printed object obtained by the selective laser sintering of the selective laser sintering composition of the present disclosure will decrease. Here, the particle size distribution D90 means that the diameter of 90% of the total volume of the powder is smaller than the value defined by the D90. According to the embodiment of the present disclosure, the particle size distribution D90 is measured according to the method specified in ISO 13322-1:2004.

According to the embodiment of the present disclosure, the weight ratio of the inorganic nano powder to the thermoplastic vulcanized elastomer powder may be about 0.2:99.8 to 0.8:99.2, for example, about 0.2:99.8, 0.3:99.7, 0.4:99.6, 0.5:99.5 , 0.6:99.4, 0.7:99.3 or 0.8:99.2. If the weight ratio of the nano-inorganic powder to the thermoplastic vulcanized elastomer powder is too high, the final printed product will decrease the physical properties due to excessive inorganic additives, and it will also increase the material cost. If the weight ratio of the nano-inorganic powder to the thermoplastic vulcanized elastomer powder is too low, the resulting selective laser sintering composition will have poor fluidity, and it will not be possible to obtain a film with a uniform thickness when the automatic powder spreading equipment is used for powder bed spreading. .

According to an embodiment of the present disclosure, the nano-inorganic powder may be silicon oxide, aluminum oxide, titanium oxide, calcium carbonate, magnesium silicate, Zinc oxide, magnesium oxide, or a combination of the above.

According to the embodiment of the present disclosure, the selective laser sintering composition may further include an additive, wherein the addition amount may be 0.1 parts by weight to 30 parts by weight, and the nano-inorganic powder and the thermoplastic vulcanizate (thermoplastic vulcanizate) , TPV) The total weight of the powder is 100 parts by weight. According to the embodiment of the present disclosure, the additive may be, for example, a dye, a pigment, an antioxidant, a stabilizer (for example, a heat stabilizer, a light stabilizer, or a hydrolysis stabilizer), a fixing agent, or the above composition.

According to an embodiment of the present disclosure, the selective laser sintering composition can be composed of a nano-inorganic powder and a thermoplastic vulcanizate (TPV) powder.

According to an embodiment of the present disclosure, the thermoplastic vulcanized elastomer powder may include a thermoplastic and a crosslinked polymer. It is worth noting that in the thermoplastic vulcanized elastomer powder described in the present disclosure, the cross-linked polymer (rubber phase) forms uniform micron-sized particles dispersed in the thermoplastic plastic (plastic phase).

The most important thing in the selective laser sintering method is the melting range of the selective laser sintering composition, which is called the sintering window (W). The thermoplastic described in the present disclosure has a sintered window W _P , and the thermoplastic vulcanized elastomer powder described in the present disclosure has a sintered window W _T. The sintering window can be measured, for example, by differential scanning calorimetry (DSC) according to the method specified in ASTM D3418.

In the differential scanning calorimetry measurement, the amount of heat supplied to the sample/the amount of heat Q removed from the sample is plotted as a function of the temperature T to obtain a differential scanning calorimetry (DSC) spectrum. The DSC chart including heating operation (H) and cooling operation (C) is depicted in Fig. 1 by way of example. First, the heating operation (H) is performed, that is, the sample and reference are heated in a linear manner. During the melting of the sample (solid phase to liquid phase), an additional amount of heat Q must be supplied to keep the sample at the same temperature as the reference. Then a peak is observed in the DSC spectrum, which is called a melting peak. After the heating operation (H), the cooling operation (C) is usually measured. During the crystallization/solidification of the sample (liquid phase to solid phase), a higher amount of heat Q must be removed to keep the sample at the same temperature as the reference, due to the release of heat during the crystallization/solidification process. In the DSC chart of the cooling operation (C), a peak in the opposite direction to the melting peak is subsequently observed, which is called a crystallization peak. The DSC spectrum can be used to determine the melting onset temperature (T _M onset) and the crystallization onset temperature (T _C onset).

In order to determine the melting onset temperature (T _M onset), the first tangent line 1 is drawn relative to the baseline of the heating operation (H) at a temperature lower than the melting peak. The second tangent line 2 is drawn with respect to the first inflection point of the melting peak at a temperature lower than the temperature at the maximum value of the melting peak. Extrapolate the two tangents until they intersect. The vertical extrapolation intersecting the temperature axis represents the melting onset temperature (T _M onset). To determine the crystallization onset temperature (T _C onset), a third tangent line 3 is drawn relative to the baseline of the cooling operation (C) at a temperature higher than the crystallization peak. A fourth tangent line 4 is drawn with respect to the inflection point of the crystallization peak at a temperature greater than the temperature at the minimum of the crystallization peak. Extrapolate the two tangents until they intersect. The vertical extrapolation that intersects the temperature axis represents the crystallization onset temperature (T _C onset). In the present disclosure, the sintering window is the difference between the _{melting onset temperature (T M} onset) and the crystallization onset temperature (T _{C onset).} Therefore, the sintering window W conforms to the following formula: W = T _M onset-T _C onset.

In the context of this disclosure, "sintering window (W)" and " _{the difference (ΔT) between the melting onset temperature (T M} onset) and the crystallization onset temperature (T _C onset)" have the same meaning and are based on Used synonymously.

According to an embodiment of the present disclosure, the difference (ΔT) (ie, the sintering window W _{P ) between the melting onset temperature (T M} onset) and the crystallization onset temperature (T _C onset t) of the thermoplastic must be greater than or equal to 10°C ( For example, it can be 10°C to 80°C, 10°C to 70°C, 10°C to 60°C, 20°C to 80°C, 20°C to 70°C, or 20°C to 60°C) to make the resulting thermoplastic vulcanized elastomer powder Has a clear and wide sintering window W _T (the onset temperature of melting (T _M onset) and the onset temperature of crystallization (T _C onset)) The difference (ΔT)). In this way, the selective laser sintering composition of the present disclosure is easy to use the selective laser sintering three-dimensional printing method to form objects, and the obtained objects have higher precision.

According to an embodiment of the present disclosure, the thermoplastic can be polyester elastomer, polypropylene, polyethylene, polyurethane, polyethylene terephthalate, polyamide, or a combination of the foregoing. According to an embodiment of the present disclosure, the number average molecular weight of the thermoplastic may be 50,000 to 500,000, so that the sintering window (W _P ) of the thermoplastic is greater than or equal to 10°C. According to an embodiment of the present disclosure, the thermoplastic can be, for example, polypropylene, polyethylene, polyurethane, polyethylene terephthalate, polyamide, or a combination of the above with _{a sintering window (W P) greater than or equal to 10°C.} According to an embodiment of the present disclosure, the thermoplastic does not include thermoplastic siloxane-based plastic or thermoplastic siloxane-based plastic. In other words, the thermoplastic plastic disclosed in the present disclosure is a polymer that does not contain silane moiety or siloxane moiety.

According to an embodiment of the present disclosure, the difference (ΔT) between the melting start temperature and the crystallization start temperature of the thermoplastic vulcanization elastomer powder (ie, the sintering window W _T ) may be greater than or equal to 10° C. (for example, it may be 10° C. to 80° C. , 10°C to 70°C, 10°C to 60°C, 20°C to 80°C, 20°C to 70°C, or 20°C to 60°C). According to the embodiment of the present disclosure, the difference (ΔT) between the melting start temperature and the crystallization start temperature of the thermoplastic vulcanization elastomer powder (that is, the sintering window W _T ) and the melting start temperature and the crystallization start temperature of the thermoplastic plastic The difference (ΔT) (ie the sintering window W _P ) is directly proportional.

According to the embodiment of the present disclosure, the weight ratio of the thermoplastic plastic to the cross-linked polymer may be about 1:1 to 1:4, for example, about 1:1, 2:3, 1:2, 3:7, 1 :3, or 1:4. If the weight ratio of the thermoplastic to the crosslinked polymer is too low (that is, the weight ratio of the thermoplastic to the crosslinked polymer is less than 0.25), the sintering window of the resulting thermoplastic vulcanizate powder may be too narrow (that is, the weight ratio of the crosslinked polymer is less than 0.25). The difference (ΔT) between the melting initiation temperature and the crystallization initiation temperature of the thermoplastic vulcanization elastomer powder is less than 10°C) or is not obvious, which in turn narrows the process window of the SLS process and affects the sinterability and sinterability of the material. Print quality. In addition, if the weight ratio of the thermoplastic to the cross-linked polymer is too high (that is, the weight of the thermoplastic is greater than the weight of the cross-linked polymer), the sintered product obtained from the selective laser sintering composition of the present disclosure is Less elastic recovery deformation characteristics.

According to an embodiment of the present disclosure, the Shore A hardness of the thermoplastic vulcanized elastomer powder may be about 50A to 98A, for example, may be about 50A, 60A, 70A, 80A, 90A, or 95A. The surface hardness (Shore Hardness, Shore Hardness A) of the thermoplastic vulcanizate powder is measured according to the method specified in ASTM D-2240.

According to an embodiment of the present disclosure, the cross-linked polymer may be a product of a rubber or/and a thermoplastic elastomer that is cross-linked in the presence of a cross-linking agent and a plasticizer.

According to the embodiment of the present disclosure, the rubber may be ethylene-propylene-diene monomer rubber (ethylene-propylene-diene monomer rubber), natural rubber (NR), polybutadiene rubber (BR), nitrile rubber ( nitrile butadiene rubber (NBR), styrene-butadiene rubber (SBR), acrylic rubber (ACM), ethylene-propylene rubber (EPR), ethylene-propylene rubber (EPR) ethylene-propylene-diene monomer rubber, EPDM), or the above composition. According to an embodiment of the present disclosure, the number average molecular weight of the rubber may be 80,000 to 1,000,000. According to embodiments of the present disclosure, the thermoplastic elastomer may be polyolefin elastomer (POE), styrene-butadiene-styrene block copolymer (SBS), benzene Ethylene-isoprene-styrene block copolymer (SIS), styrene-ethylene/butylene-styrene block copolymer (styrene-ethylene/butylene-styrene block copolymer) copolymer (SEBS), styrene-ethylene/propylene-styrene block copolymer (SEPS), or the above composition. According to an embodiment of the present disclosure, the polyolefin elastomer (POE) may be a polymer or copolymer of an olefin-based monomer (for example, an α-olefin-based monomer). For example, the olefin-based monomer can be ethylene, propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene Ene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-di Methyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, isoprene, tetrafluoroethylene, 1-decene, 1-decene Diene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, cyclobutene, cyclopentene, cyclohexene, cyclooctene, 1,3-butadiene , 1,3-pentadiene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2-(2-methylbutyl)-1-cyclohexene, 1,4-hexene Diene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 7-methyl-1,6-octadiene, 3,7-dimethyl- 1,6-octadiene, 5,7-dimethyl-1,6-octadiene, 1,7-octadiene, 3,7,11-trimethyl-1,6,10-octadiene Ene, 6-methyl-1,5-heptadiene, 1,6-heptadiene, 1,8-nonadiene, 1,9-decadiene, or 1,10-undecadiene. In addition, according to embodiments of the present disclosure, the polyolefin elastomer may be polyethylene (PE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), polypropylene, poly (Propylene-α-olefin), ethylene-propylene copolymer (EPC), poly(ethylene-α-olefin), poly(ethylene-octene), poly(ethylene-hexene), poly(ethylene-butene), Poly(ethylene-heptene), polybutene, polypentene, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), or ethylene-butyl acrylate (EBA). According to an embodiment of the present disclosure, the number average molecular weight of the thermoplastic elastomer may be 50,000 to 300,000.

According to embodiments of the present disclosure, the crosslinking agent may be peroxide, phenolic resin, sulfur, sulfide, carbodiimide compound, aliphatic diamine, or a combination of the foregoing.

According to an embodiment of the present disclosure, the peroxide may be dicumyl peroxide (DCP), perbutyl peroxide (PBP), dimethyl-di-tert-butyl peroxide Hexane, tert-butyl ethylhexyl monoperoxy carbonate, di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 2,5 -Dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne, di-tert-butylperoxycumene, 1,1-di-tert-butylperoxy-3,3, 5-trimethylcyclohexane, 4,4-di(tert-butylperoxy) n-butyl valerate, benzoyl peroxide, p-chlorobenzyl peroxide, 2,4-dichlorobenzene peroxide Formaldehyde, tert-butyl peroxybenzoate, tert-butyl peroxy isopropyl formate, diethyl peroxide, laurel peroxide, tert-butyl cumene peroxide, or a combination of the above. According to an embodiment of the present disclosure, the phenolic resin may be formed by the condensation reaction of a phenol compound and an aldehyde compound, wherein the phenol compound may be 4-t-butylphenol or 4-octylphenol (4-t-octylphenol), 2-ethylphenol, 3-ethylphenol, 4-ethylphenol, o-cresol, M-cresol (m-cresol), p-cresol (p-cresol), 2,5-xylenol (2,5-xylenol), 3,4-xylenol (3,4-xylenol), 3, 5-xylenol (3,5-xylenol), 2,3,5-trimethylphenol (2,3,5-trimethylphenol), 3-methyl-6-tert-butylphenol (3-methyl-6-t -butylphenol, 2-naphthol, 1,3-dehydroxynaphthalene, bisphenol-A, or a combination of the above; and, the aldehyde compound can be It is formaldehyde, paraformaldehyde, acetoaldehyde, benzaldehyde, phenylaldehyde, or a combination of the above. According to an embodiment of the present disclosure, the sulfide may be tetrabenzylthiuram disulfide, dibenzothiazole disulfide, or a combination of the foregoing. According to an embodiment of the present disclosure, the carbodiimide compound may be 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide), N,N'-dicyclohexylcarbodiimide (N,N'-dicyclohexylcarbodiimide), or a combination of the above. According to the embodiment of the present disclosure, the aliphatic diamine can be hexamethylene diamine, octane diamine, nonane diamine, decane diamine, 1,16-hexadecane diamine (1,16-Hexadecane diamine), 1,18 -Octadecane diamine (1,18-Octadecane diamine), or a combination of the above.

According to an embodiment of the present disclosure, the plasticizer can be silicone oil, mineral oil, paraffin oil, or a combination of the foregoing.

According to the embodiment of the present disclosure, the preparation method of the thermoplastic vulcanized elastomer powder may include the following steps. First, a thermoplastic and a rubber (and/or thermoplastic elastomer) are mixed into a blend. Then, a crosslinking agent and a plasticizer are added to cause crosslinking and vulcanization between the rubber (and/or thermoplastic elastomer) in the blend, and through the shearing force generated during crosslinking, the original The continuous rubber phase is dispersed in the plastic phase to form a reverse rotation to obtain a thermoplastic vulcanized elastomer. After drying, grinding, and sieving the thermoplastic vulcanized elastomer, the thermoplastic vulcanized elastomer powder is obtained. The "mixing" mentioned in this disclosure refers to the process of uniformly mixing rubber or plastic with various reagents (such as crosslinking agents and plasticizers) by mechanical action. The mixing step can also be carried out in a discontinuous or batch method. .

According to the embodiment of the present disclosure, the manufacturing method of the thermoplastic vulcanized elastomer can be a dynamic cross-linking process. The term dynamic crosslinking refers to the process of kneading the crosslinking agent and the mixture during the melt blending of the rubber and plastic in the mixture to form crosslinks between the rubbers. The term "dynamic" means that the mixture exerts shear force during the cross-linking step. In order to better melt and blend rubber and plastic, the temperature during the blending period can be adjusted to be between the melting point temperature and the decomposition temperature of the plastic used.

The present disclosure also provides a selective laser sintering three-dimensional printing method, which uses the above-mentioned selective laser sintering composition to perform three-dimensional printing. The method includes: (A) forming a film layer, wherein the film layer is composed of the above-mentioned selective laser sintering composition; (B) scanning the film layer selectively with a laser beam to cure the selective laser Sintering the composition to form a part of an object; and (C) repeat steps (A) and (B) until the object is formed.

According to an embodiment of the present disclosure, the film layer may be a film thickness commonly used in the conventional selective laser sintering three-dimensional printing method, for example, 80 μm to 150 μm. According to an embodiment of the present disclosure, a laser suitable for selective laser sintering is known to those familiar with the technology, such as Nd: YAG laser (neodymium-doped yttrium aluminum garnet). laser), or carbon dioxide laser.

In order to make the above and other objectives, features, and advantages of the present disclosure more obvious and understandable, the following specific examples with accompanying drawings are described in detail as follows:

Thermoplastic vulcanized elastomer powder preparation example 1: 70 parts by weight of ethylene propylene diene rubber (EPDM) (manufactured and sold by DOW, product number NORDEL™ 4570), 30 parts by weight of polypropylene (PP) (manufactured by Li Manufactured and sold by Evergreen Chemical, the product number is 9580) (melting starting temperature is 147.2 ℃, crystallization starting temperature is 132.6 ℃, difference (ΔT) is 14.6 ℃), 1.5 parts by weight of peroxide (by Jianxin The company manufactures and sells, the product number is DCP) as a cross-linking agent, and 40 parts by weight of mineral oil (manufactured and sold by Chaohui Company, the product number is FOMI-250) is added as a plasticizer to the kneader (model number) For JKM-DK10), and at a temperature of 150 ℃, 50-100rpm. After kneading for 20 minutes, a pelletizer (model GZML-110L-150) was used to pelletize at a temperature of 50-100° C. and a screw rotation speed of 20 rpm to obtain a thermoplastic vulcanized elastomer masterbatch. Next, the thermoplastic vulcanization elastomer masterbatch was placed in liquid nitrogen using a grinder for freezing grinding and sieving to obtain thermoplastic vulcanization elastomer powder (1) with a particle size distribution D90 of about 82 μm and a particle size distribution D90 of about 146μm thermoplastic vulcanized elastomer powder (2). _{The hardness and the sintering window W T of the} obtained thermoplastic vulcanization elastomer powders (1) and (2) were measured, and the results are shown in Table 1.

Preparation Example 2: 60 parts by weight of EPDM (manufactured and sold by DOW, the product number is NORDEL™ 4570) and 40 parts by weight of polypropylene (PP) (manufactured and sold by Li Changrong Chemical) Sold under the product number 9580) (melting starting temperature is 147.2 ℃, crystallization starting temperature is 132.6 ℃, difference (ΔT) is 14.6 ℃), 1.2 parts by weight of peroxide (manufactured and sold by Jianxin Company , The product number is DCP) as a crosslinking agent, and 30 parts by weight of mineral oil (manufactured and sold by Chaohui Company, the product number is FOMI-250) as a plasticizer, added to the kneader (model JKM-DK10) Medium, and at a temperature of 150 °C, 50-100 rpm. After kneading for 20 minutes, a pelletizer (model GZML-110L-150) was used to pelletize at a temperature of 50-100° C. and a screw rotation speed of 20 rpm to obtain a thermoplastic vulcanized elastomer masterbatch. Next, the thermoplastic vulcanization elastomer masterbatch was placed in liquid nitrogen using a grinder for freezing grinding and sieving to obtain a thermoplastic vulcanization elastomer powder (3) with a particle size distribution D90 of about 91 μm. _{The hardness and sintering window W T of the} obtained thermoplastic vulcanization elastomer powder (3) were measured, and the results are shown in Table 1.

Preparation Example 3: Preparation Example 3 was carried out as described in Preparation Example 2, except that the weight ratio of EPDM and PP was adjusted from 60:40 to 80:20 to obtain thermoplastic vulcanized elastomer powder (4) with a particle size distribution D90 of about 85μm. ). _{The hardness and sintering window W T of the} obtained thermoplastic vulcanized elastomer powder (4) were measured, and the results are shown in Table 1.

Preparation Example 4: Preparation Example 4 was performed as described in Preparation Example 2, except that the weight ratio of EPDM and PP was adjusted from 60:40 to 50:50 to obtain thermoplastic vulcanized elastomer powder (5) with a particle size distribution D90 of about 81 μm. ). _{The hardness and the sintering window W T of the} obtained thermoplastic vulcanization elastomer powder (5) were measured, and the results are shown in Table 1.

Table 1 Rubber (or elastomer) plastic The weight ratio of rubber (or elastomer) to plastic Particle size distribution D90 (μm) Hardness (Shore A) Sintering window W _T (℃) Thermoplastic vulcanized elastomer powder (1) EPDM PP 70:30 82 60 14.6 Thermoplastic vulcanized elastomer powder (2) EPDM PP 70:30 146 60 13.1 Thermoplastic Vulcanized Elastomer Powder (3) EPDM PP 60:40 91 72 14.3 Thermoplastic vulcanized elastomer powder (4) EPDM PP 80:20 85 51 13.8 Thermoplastic vulcanized elastomer powder (5) EPDM PP 50:50 81 86 12.6

Preparation Example 5: 70 parts by weight of styrene-ethylene/butylene-styrene block copolymer (SEBS) (manufactured and sold by TSRC, the product number is Taipol 6014) and 30 parts by weight of polypropylene ( PP) (manufactured and sold by Li Changrong Chemical, product number 8681) (melting starting temperature is 142.8 ℃, crystallization starting temperature is 121.5 ℃, difference (ΔT) is 21.3 ℃), 1.2 parts by weight of peroxide (Manufactured and sold by Arkema, product number is Luperox® 101) as a crosslinking agent, and 80 parts by weight of mineral oil (manufactured and sold by Chaohui Company, product number is FOMI-550) as a plasticizer, Add to a kneader (model JKM-DK10), and at a temperature of 150 ℃, 50-100 rpm. After kneading for 20 minutes, a pelletizer (model GZML-110L-150) was used to pelletize at a temperature of 50-100° C. and a screw rotation speed of 20 rpm to obtain a thermoplastic vulcanized elastomer masterbatch. Next, the thermoplastic vulcanization elastomer masterbatch was placed in liquid nitrogen using a grinder for freezing grinding and sieving to obtain a thermoplastic vulcanization elastomer powder (6) with a particle size distribution D90 of about 86 μm. _{The hardness and the sintering window W T of the} obtained thermoplastic vulcanization elastomer powder (6) were measured, and the results are shown in Table 2.

Preparation Example 6: Preparation Example 6 was carried out as described in Preparation Example 5, except that SEBS was replaced with styrene-ethylene/butylene-styrene block copolymer (SEPS) (manufactured and sold by Kraton Corporation, the product number is G1730) to obtain thermoplastic vulcanized elastomer powder (7) with a particle size distribution D90 of about 79 μm. _{The hardness and the sintering window W T of the} obtained thermoplastic vulcanization elastomer powder (7) were measured, and the results are shown in Table 2.

Preparation Example 7: Preparation Example 7 was performed as described in Preparation Example 5, except that SEBS was replaced with acrylic rubber (ACM) (manufactured and sold by ZEON, the product number is AR-51), and PP was replaced with polyamide Amine (Nylon) (manufactured and sold by Taihua Company, the product number is PA6N) (melting starting temperature is 203.2 ℃, crystallization starting temperature is 181.5 ℃, difference (ΔT) is 21.7 ℃), and the particle size distribution is obtained D90 is 88 μm thermoplastic vulcanized elastomer powder (8). _{The hardness and sintering window W T of the} obtained thermoplastic vulcanized elastomer powder (8) were measured, and the results are shown in Table 2.

Preparation Example 8: Preparation Example 8 was carried out as described in Preparation Example 5, except that SEBS was replaced with natural rubber (NR) (manufactured and sold by Pufei Chemical, the product number is 3L), and the particle size distribution D90 was about 95μm. The thermoplastic vulcanized elastomer powder (9). _{The hardness and sintering window W T of the} obtained thermoplastic vulcanization elastomer powder (9) were measured, and the results are shown in Table 2.

Comparative Example 1 100 parts by weight of a thermoplastic polyester elastomer (TPEE) (manufactured and sold by DuPont, the product number is 4056) was frozen and ground in liquid nitrogen using a grinder and sieved to obtain a particle size distribution D90 It is about 86μm TPEE powder. The results of measuring the hardness of TPEE powder are shown in Table 2. The TPEE powder obtained was analyzed by differential scanning calorimetry (DSC). Because the melting peak of the TPEE powder was too broad and very close to the crystallization peak, the sintering window W _p could not be measured.

Comparative Example 2 100 parts by weight of polyurethane (TPU) (manufactured and sold by Lubrizol, product number S385A) was placed in liquid nitrogen with a grinder for freezing and sieving to obtain TPU with a particle size distribution D90 of about 80 μm powder. The results of measuring the hardness of the TPU powder are shown in Table 2. The TPU powder obtained was analyzed by differential scanning calorimetry (DSC). Because the melting peak of the TPU powder was too broad and very close to the crystallization peak, the sintering window W _p could not be measured.

Table 2 Rubber (or elastomer) plastic The weight ratio of rubber (or elastomer) to plastic Particle size distribution D90 (μm) Hardness (Shore A) Sintering window W _T (℃) Thermoplastic Vulcanized Elastomer Powder (6) SEBS PP 70:30 86 52 16 Thermoplastic Vulcanized Elastomer Powder (7) SEPS PP 70:30 79 63 15 Thermoplastic Vulcanized Elastomer Powder (8) ACM Nylon 70:30 88 95 twenty two Thermoplastic Vulcanized Elastomer Powder (9) NR PP 70:30 95 90 17 TPEE powder - TPEE - 86 92 none TPU powder - TPU - 80 94 none

Selective laser sintering composition Example 1 99.8 parts by weight of the thermoplastic vulcanized elastomer powder (1) and 0.2 parts by weight of silicon dioxide powder (particle size distribution D90 of 20 nm) are uniformly mixed to obtain a selective laser sintering composition (1). The selective laser sintering composition (1) was tested for fluidity, and the results are shown in Table 3. Next, the selective laser sintering composition (1) was subjected to selective laser sintering three-dimensional printing (film thickness of 150μm, powder bed temperature of 140℃) to obtain a test piece, and the tensile strength of the test piece Test and 3D printing accuracy test, the results are shown in Table 3. The tensile strength of the test piece is measured in accordance with the method specified in ASTM D412. The three-dimensional printing accuracy test is to observe whether the shape of a square hole with a side length of 2mm designed on the test piece formed by the selective laser sintering composition is complete (if there are residual burrs or holes deformed, it will be considered Incomplete shape), if the square hole is complete, it is deemed to have passed the accuracy test.

Example 2-9 Examples 2-9 were carried out in the manner described in Example 1, except that the thermoplastic vulcanization elastomer powder (1) was replaced with the thermoplastic vulcanization elastomer powder (2)-(9), respectively, to obtain the selective laser sintering composition (2) )-(9). Next, the selective laser sintering compositions (2)-(9) were tested for fluidity, and the results are shown in Table 3. Next, perform selective laser sintering three-dimensional printing on the selective laser sintering compositions (2)-(9) respectively (the film thickness is 150μm; the thermoplastic vulcanized elastomer powders (2)-(7) and (9) The temperature of the powder bed is 140℃, the temperature of the powder bed of the thermoplastic vulcanization elastomer powder (8) is 190℃) to obtain test pieces, and the tensile strength test and three-dimensional printing accuracy test of these test pieces are carried out. The results are shown in Table 3. Shown.

Comparative example 3 Comparative Examples 3 and 4 were carried out in the manner described in Example 1, except that the thermoplastic vulcanized elastomer powder (1) was replaced with the TPEE powder described in Comparative Example 1 and the TPU powder described in Comparative Example 2, respectively, to obtain a selective laser sintering combination物(10) and (11). Next, the selective laser sintering compositions (10) and (11) were tested for fluidity, and the results are shown in Table 3. Next, perform selective laser sintering three-dimensional printing on the selective laser sintering compositions (10) and (11) respectively (the film thickness is 150μm, the powder bed temperature of TPEE powder is 120℃, and the powder bed temperature of TPU powder is (90° C.) to obtain test pieces, and perform tensile strength test and three-dimensional printing accuracy test on these test pieces. The results are shown in Table 3.

table 3 Powder Liquidity (Angle of Response) Tensile strength (Kg/cm ² ) 3D printing accuracy test Example 1 Selective laser sintering composition (1) 22.5 65 pass Example 2 Selective laser sintering composition (2) 42.3 twenty three Did not pass Example 3 Selective laser sintering composition (3) 26.1 89 pass Example 4 Selective laser sintering composition (4) 21.9 60 pass Example 5 Selective laser sintering composition (5) 23.6 96 pass Example 6 Selective laser sintering composition (6) 27.5 59 pass Example 7 Selective laser sintering composition (7) 25.3 82 pass Example 8 Selective laser sintering composition (8) 25.9 101 pass Example 9 Selective laser sintering composition (9) 24.6 55 pass Comparative example 3 Selective laser sintering composition (10) 29.5 30 Did not pass Comparative example 4 Selective laser sintering composition (11) 28.4 70 Did not pass

The thermoplastic vulcanizate powder used in the selective laser sintering composition (1) and the selective laser sintering composition (2) have the same material, and the only difference is that the selective laser sintering composition (1) is used The particle size distribution D90 of the thermoplastic vulcanization elastomer powder is less than 100 µm, and the particle size distribution D90 of the thermoplastic vulcanization elastomer powder used in the selective laser sintering composition (2) is greater than 100 µm. It can be seen from Table 3 that when the particle size distribution D90 of the plastic vulcanized elastomer powder used is greater than 100 µm, the resulting test piece cannot pass the three-dimensional printing accuracy test. In addition, the tensile strength of the test piece prepared by the selective laser sintering composition (10) containing TPEE powder is obviously poor. Furthermore, since the TPEE powder and TPU powder do not have a sintering window W _T (or the sintering window W _{T is} less than 10°C), it is not easy for these powders to form objects using selective laser sintering three-dimensional printing methods, and the resulting objects Has poor accuracy.

Although this disclosure has been disclosed in several embodiments as above, it is not intended to limit this disclosure. Anyone with ordinary knowledge in the art can make any changes and modifications without departing from the spirit and scope of this disclosure. Therefore, the protection scope of this disclosure shall be subject to those defined by the attached patent application scope.

1: the first all line 2: second tangent 3: third tangent 4: The fourth tangent

FIG. 1 is a schematic diagram of a selective laser sintering composition according to an embodiment of the disclosure.

1: the first all line

2: second tangent

3: third tangent

4: The fourth tangent

Claims (12)

A selective laser sintering composition, comprising: a nanometer inorganic powder, wherein the inorganic powder has a particle size distribution D90 value of 1nm to 950nm; and a thermoplastic vulcanized elastomer powder, wherein the thermoplastic vulcanized elastomer powder is melted The difference (ΔT) between the initial temperature and the initial crystallization temperature (ΔT) is greater than or equal to 10°C, wherein the particle size distribution D90 of the thermoplastic vulcanization elastomer powder is 40 µm to 100 µm, and the thermoplastic vulcanization elastomer powder includes: a thermoplastic , Wherein the difference (ΔT) between the melting initiation temperature and the crystallization initiation temperature of the thermoplastic is greater than or equal to 10°C; and a cross-linked polymer, wherein the cross-linked polymer is a cross-linked rubber. Linked thermoplastic elastomer, or a combination thereof, wherein the weight ratio of the thermoplastic plastic to the cross-linked polymer is 1:1 to 1:4. For example, the selective laser sintering composition described in item 1 of the scope of patent application, wherein the weight ratio of the inorganic nano powder to the thermoplastic vulcanized elastomer powder is 0.2:99.8 to 0.8:99.2. According to the selective laser sintering composition described in item 1 of the scope of patent application, the Shore A hardness of the thermoplastic vulcanized elastomer powder is 50A to 98A. The selective laser sintering composition described in item 1 of the scope of patent application, wherein the inorganic nano powder is silica, alumina, titanium oxide, calcium carbonate, magnesium silicate, zinc oxide, magnesium oxide, or a combination of the above . The selective laser sintering composition described in item 1 of the scope of patent application, wherein the thermoplastic plastic is polypropylene, polyethylene, polyurethane, polyethylene terephthalate, polyamide, or a combination of the above. The selective laser sintering composition described in item 1 of the scope of patent application, wherein the cross-linked polymer is a rubber or/and a thermoplastic elastomer which is cross-linked in the presence of a cross-linking agent and a plasticizer的产品。 The product. The selective laser sintering composition described in item 6 of the scope of patent application, wherein the rubber is EPDM rubber, natural rubber, polybutadiene rubber, nitrile rubber, styrene butadiene rubber, acrylate rubber , Ethylene propylene rubber, EPDM rubber, or the above composition. The selective laser sintering composition described in item 6 of the scope of patent application, wherein the thermoplastic elastomer system, polyolefin elastomer, styrene-butadiene-styrene block copolymer, styrene-isoprene -Styrenic triblock copolymer, styrene-ethylene/butylene-styrene block copolymer, styrene-ethylene/butylene-styrene block copolymer, or the above composition. The selective laser sintering composition described in item 6 of the scope of patent application, wherein the crosslinking agent is peroxide, phenolic resin, sulfur, sulfide, carbodiimide compound, aliphatic diamine, or a combination of the above . The selective laser sintering composition described in item 6 of the scope of patent application, wherein the plasticizer is silicone oil, mineral oil, paraffin oil, or a combination of the above. The selective laser sintering composition described in item 1 of the scope of patent application further includes: An additive, wherein the additive is a dye, a pigment, an antioxidant, a stabilizer, a fixing agent, or the above composition. A selective laser sintering three-dimensional printing method, including: (A) forming a film layer, wherein the film layer comprises the selective laser sintering composition according to any one of the patent applications 1 to 10; (B) Scanning with a laser beam to selectively irradiate the film to cure the selective laser sintering composition to form a part of an object; and (C) Repeat steps (A) and (B) until the object is formed.

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