JP2010214858A - Method of selective laser sintering using powder of specific resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide resin which can be satisfactorily fluidized by heating and a method of Selective Laser Sintering using the resin. <P>SOLUTION: In the method of Selective Laser Sintering using powder of the specific resin, the resin is made to be an elliptic column-shaped pellet in which the long diameter of the ellipse is 2-5 mm, the short diameter is 1-4 mm, and the height is 1-5 mm. The pellet is heated for 30 minutes at temperature t(K), in which T, defined by a formula of T=t/Tg, is within a range from 1.10 to 1.40 to glass transition temperature Tg(K) of the resin. a2 denotes the maximum projected area of the object obtained by heating which is deformed from the pellet before being heated, a1 denotes the maximum projected area of the pellet before being heated, and A denotes a ratio of a2 and a1 (a2/a1). Within the range of T from 1.10 to 1.40, three or more values of A corresponding to optional T are obtained. When A is expressed as a linear function of T by linear regression based on a relationship between the obtained A and T, the linear function satisfies specific conditions, which characterizes the specific resin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a powder sintering additive manufacturing method. More specifically, the present invention relates to a powder sintering additive manufacturing method that uses a resin suitable for the powder sintering additive manufacturing method, which becomes highly fluid when heated.

  The powder sintering additive manufacturing method (Selective Laser Sintering, hereinafter also referred to simply as SLS) creates data of cross-sectional shapes (first to nth cross-sectional data) at predetermined intervals in advance of the target model, A thin layer of resin / metal powder spread at a constant interval is heated by scanning and irradiating a laser with a cross-sectional shape corresponding to the data of the first cross section, thereby fusing the resin or metal. Sintering and then laying resin and metal powder again at a constant interval on it, and repeatedly laminating the laser by scanning the cross-sectional shape corresponding to the data of the second cross-section This is a technique for manufacturing a modeled object. For example, Patent Document 1 discloses the technique.

  In SLS, resin powder or metal powder is fluidized, fused, and sintered by being irradiated with a laser, but if this fluidization is insufficient, bubbles ( This is a gap formed by insufficient fusion between resin powders or metal powders), and the transparency of the molded article is deteriorated and the strength thereof is insufficient. For example, polycarbonate, polystyrene, polymethyl methacrylate, etc. are inherently transparent resins, but even when powders made of such resins are used in SLS, the resin fluidity is insufficient or the molding conditions can be optimized. If it is insufficient, the fusion between the powder and the powder does not proceed sufficiently, and a gap is formed in the vicinity of the fusion part and becomes opaque. This is because the void portion is a gas component in the modeling atmosphere such as air or nitrogen, and the refractive index with the resin is remarkably different and light is diffusely reflected. Therefore, there is a strong demand for the development of SLS using a resin that hardly generates such a gas phase portion, that is, has a high resin filling rate in an SLS modeling environment.

WO1997 / 029148 Pamphlet

  The present invention provides an SLS using a resin capable of producing a molded article having a small number of voids and excellent transparency by allowing fusion between resin powders to proceed easily by heating and sufficiently fluidizing. Objective.

As a result of intensive studies to solve the above problems, the present inventors have found that a resin satisfying a specific condition is suitable for SLS, and have completed the present invention.
That is, the powder sintering additive manufacturing method of the present invention is
A powder sintering additive manufacturing method using a specific resin powder,
The specific resin is
The resin is an elliptical columnar pellet having an elliptical major axis of 2 to 5 mm, a minor axis of 1 to 4 mm, and a height of 1 to 5 mm,
The pellet has a T defined by T = t / Tg (Tm) with respect to the glass transition temperature Tg (K) of the resin (melting point Tm (K) in the case of a crystalline resin) of 1.10 ≦ T ≦ 1. The maximum projected area of a product obtained by deforming a pellet before heating obtained by heating at a temperature t (K) in the range of 1.40 for 30 minutes is defined as a2 (K represents an absolute temperature). The maximum projected area is a1, the ratio of a2 to a1 (a2 / a1) is A,
1. In the range of 10 ≦ T ≦ 1.40, obtain three or more values of A corresponding to any T, and express A as a linear function of T by linear regression from the relationship between A and T obtained In addition,
In the powder sintering additive manufacturing method, the slope of the linear function is 5.0 or more, and A is 1.05 or more when T is 1.25 in the linear function.

The specific resin is preferably an amorphous resin or a semicrystalline resin having transparency.
Moreover, it is preferable that the glass transition temperature (in the case of crystalline resin, melting | fusing point) of the said specific resin is 100-200 degreeC.

The volume average particle diameter of the specific resin powder is usually 1 to 200 μm.
By the powder sintering additive manufacturing method of the present invention, a molded article having excellent transparency and strength can be obtained.
Further, from the powder sintering additive manufacturing method of the present invention, a method for screening a resin suitable for SLS is derived, and the screening method is:
Step 1 of producing an elliptical columnar pellet having a major axis of an ellipse of 2 to 5 mm, a minor axis of 1 to 4 mm, and a height of 1 to 5 mm from the test resin;
Determining the maximum projected area a1 of the pellet;
The pellet has a T defined by T = t / Tg (Tm) with respect to the glass transition temperature Tg (K) of the resin (melting point Tm (K) in the case of a crystalline resin) of 1.10 ≦ T ≦ Step 3 (K represents an absolute temperature), which is deformed by heating for 30 minutes at a temperature t (K) in the range of 1.40,
Step 4 for obtaining the maximum projected area a2 of the deformation of the pellet before heating obtained in Step 3;
Calculating a corresponding T from the temperature t;
Step 6 for calculating a ratio A (a2 / a1) of a2 and a1;
Steps 7 to 6 are repeated twice or more by changing the temperature t, and
Step 8 expressing A as a linear function of T by linear regression from the relationship between the plurality of T obtained from Steps 5 to 7 and A corresponding to each T;
When the slope of the linear function is 5.0 or more and A is 1.05 or more when T is 1.25 in the linear function, the test resin is used in the powder sintering additive manufacturing method. And step 9 for determining that the resin is suitable for the above.

  ADVANTAGE OF THE INVENTION According to this invention, SLS using resin which can manufacture the modeling thing excellent in transparency with few voids fully fluidized by heating is provided.

[Powder Sinter Laminate Method of the Present Invention]
In the powder sintering additive manufacturing method of the present invention, the thin layer of resin powder is heated by scanning and irradiating a thin layer of resin powder, whereby the thin layer of resin powder is fused and sintered. A three-dimensional structure is created by sequentially laminating, that is, forming a thin layer of resin powder again on a thin layer that has been sintered, and repeating laser beam irradiation to fuse and sinter the thin layer. , A powder sintering additive manufacturing method using a specific resin powder,
The specific resin is
The resin is an elliptical columnar pellet having an ellipse major axis of 2 to 5 mm, a minor axis of 1 to 4 mm, and a height of 1 to 5 mm, and the pellet has a glass transition temperature Tg (K) of the resin (described above) When the resin is a crystalline resin, the temperature t (K) at which T defined by T = t / Tg (Tm) with respect to the melting point Tm (K) is in the range of 1.10 ≦ T ≦ 1.40 The maximum projected area of the deformed pellet before heating, which is obtained by heating for 30 minutes, is a2 (K represents absolute temperature), the maximum projected area of the pellet before heating is a1, and a2 and a1 The ratio (a2 / a1) of A is A, and within a range of 1.10 ≦ T ≦ 1.40, three or more values of A corresponding to arbitrary T are obtained, and linear regression is performed from the obtained relationship between A and T. When A is expressed as a linear function of T, the slope of the linear function is 5.0 or more, and when T is 1.25 in the linear function, A is 1 It is characterized in that it is 05 or more. Hereinafter, each of the above-described structures of the specific resin used in the present invention will be described in detail.

<T (absolute temperature ratio)>
T is a ratio (t / Tg (Tm) between the temperature t (K) for heating the pellet of the specific resin and the glass transition temperature Tg (K) of the resin (melting point Tm (K) in the case of crystalline resin). )). Said K is an absolute temperature. For example, if the temperature for heating the resin pellets is 250 ° C., t is 523K.

  In addition, in this specification, a glass transition temperature is an extrapolated glass transition temperature calculated | required according to Japanese Industrial Standard K7121 using the differential scanning calorimeter (SII nanotechnology company make, brand name: DSC6220). The melting point is the melting peak temperature determined according to K7121.

  The temperature t at which the specific resin pellet is heated can be arbitrarily determined so that T is in the range of 1.10 to 1.40 depending on the type of resin (glass transition temperature or melting point).

  As described later, the present invention heats the pellet of the specific resin at a heating temperature at which T is in the range of 1.10 to 1.40, deforms the pellet, and A corresponding to any T (before and after heating) The ratio of the maximum projected area of the pellets) is at least three points, and when A is expressed as a linear function of T by linear regression from the relationship between A and T obtained, the slope of the linear function is 5.0. When a resin having A of 1.05 or more when T is 1.25 in the linear function is used for SLS, the resin exhibits good fluidity under SLS heating conditions even under low load, This is based on the finding that it is possible to produce a molded article with less transparency.

<A (ratio of maximum projected area)>
A is a2 and a1, where a1 is the maximum projected area of the pellet, and a2 is the maximum projected area of the deformed pellet obtained by heating the pellet for 30 minutes at the temperature t. Ratio (a2 / a1).

The pellet is a resin solid in the shape of an elliptic cylinder as described above, and the major axis of the ellipse is 2 to 5 mm, the minor axis is 1 to 4 mm, and the height is 1 to 5 mm.
The maximum projected area is the area of the projected view where the area is maximum in the projected view when the pellet is projected from all angles. “Projection” is synonymous with “projection” used in mathematics, that is, a parallel light beam is applied to an object and its shadow is projected on a plane. Therefore, the projected area is the same as the front view area. The frontal view area is the area of a figure drawn on a front view when an object is viewed.

Therefore, the maximum projected area means the maximum area among the frontal viewing areas when the object is viewed from all angles.
a2 is the maximum projected area of the deformed pellet before heating obtained by heating the resin pellet at temperature t for 30 minutes as described above. Since t is set to satisfy 1.10 ≦ T ≦ 1.40 as described above, t is higher than the glass transition temperature Tg or the melting point Tm of the resin. Therefore, when the resin pellet is heated at a temperature t for 30 minutes, the resin pellet generally fluidizes and deforms from a solid state into a disk shape and spreads. Therefore, a2 is usually the area of the disk.

<Primary function>
The specific resin used in the present invention obtains three or more values of A corresponding to any T in the range of 1.10 ≦ T ≦ 1.40 for A and T defined as described above. When A is expressed as a linear function of T by linear regression from the relationship between A and T obtained, when the slope of the linear function is 5.0 or more and T is 1.25 in the linear function, A is characterized by being 1.05 or more.

That is, for example, if A corresponding to T ₁ is A ₁ , A corresponding to T ₂ is A ₂ , and A corresponding to T ₃ is A ₃ , then (T ₁ , A ₁ ), (T ₂ , A ₂ , ) And (T ₃ , A ₃ ), and linear regression is performed by the least squares method to represent A as a linear function of T. The obtained linear function is expressed as follows, for example.
A = xT + B (B is a constant)

  The specific resin used in the present invention is such that x is 5.0 or more and 1.25x + B is 1.05 or more in the above linear formula. There is no particular upper limit to the number of A and T data for obtaining a linear function by linear regression, but it is usually sufficient to obtain three-point data.

  A (ratio of the maximum projected area before and after heating of the pellet) and T (ratio of the heating temperature and the glass transition temperature or melting point of the resin) usually have a linear relationship within the range of T = 1.10 to 1.40. Although depending on the type of resin, in an excessively high temperature range, the resin tends to reduce its specific surface area, so that it deforms into a spherical shape, and A and T may deviate from a linear relationship. In the present invention premised on use in SLS, the resin is used in an environment where the resin melts and spreads by heat, that is, in a temperature range (approximately 200 to 350 ° C.) in which a direct relationship is expressed.

  A is a numerical value indicating how much the maximum projected area is increased because the resin is fluidized by heating and deformed into a disk shape, and the larger the A, the higher the fluidity of the resin due to heating. That is, the fluidization ability of the resin is high. When A is small, the resin does not fluidize very much by heating, so as described in [Background Technology], bubbles are formed in the shaped product obtained by SLS (gap that can be formed by insufficient fusion of resin powders). Exists, and the transparency and strength of the molded article are insufficient.

Further, x (gradient of the linear function) is a numerical value indicating how much the resin is more fluidized by raising the heating temperature, and the greater the x, the higher the fluidization capability of the resin.
From the above, it can be said that a resin having a large numerical value A and x is suitable for SLS. However, as a result of various investigations, the present inventors have found that when x is 5.0 or more and T is 1.25. Resin with a corresponding A (= 1.25x + B) of 1.05 or more is excellent in fluidization ability, and therefore, by SLS processing, it is excellent in transparency without bubbles, and has a sufficient strength. I found out that I can do it. Resins with x less than 5.0 or A less than 1.05 when T is 1.25 have insufficient fluidization capability and bubbles when applied to powder sintered additive manufacturing. It is not preferable because it causes deterioration of transparency or insufficient strength in the molded product.

  The A value is preferably 1.1 or more, more preferably 1.2 or more, particularly preferably 1.3 or more, and usually 4 or less, from the viewpoint of the fluidization ability of the resin used in the present invention. Further, x (gradient of the linear function) is preferably 6.0 or more, more preferably 7.0 or more, particularly preferably 8.0 or more, and usually 20 or less from the viewpoint of fluidization ability.

<Specific resin>
The specific resin used in the present invention is a resin that satisfies the above-described requirements, and has excellent fluidization ability. Therefore, when applied to SLS, a molded article excellent in transparency and strength can be produced.

  The glass transition temperature of the specific resin used in the present invention (melting point when the specific resin is a crystalline resin) is usually 100 to 200 ° C., preferably 100 to 190 ° C., more preferably 100 to 185 ° C., particularly Preferably it is 100-180 degreeC. If the glass transition temperature (melting point) exceeds 200 ° C, the processability in SLS may increase, resulting in poor processability. On the other hand, if the glass transition temperature (melting point) is less than 100 ° C, the heat resistance may be insufficient and the practicality may be lacking. is there.

  In addition, the specific resin used in the present invention, as described above, obtained three or more values of A corresponding to any T in the range of 1.10 ≦ T ≦ 1.40, and obtained A and T From the relationship, when A is expressed as a linear function of T by linear regression, the slope x of the linear function is 5.0 or more, and when T is 1.25 in the linear function, A is 1.05 or more. is there.

  In order to set the slope x to 5.0 or more, the molecular structure of the specific resin is a molecular structure with weak electronic interaction between molecules, and a molecular structure in which entanglement of molecular chains between molecules hardly occurs. It is desirable to shorten the molecular chain of the specific resin.

  In order to make A be 1.05 or more when T is 1.25, the molecular structure of the specific resin is changed to a molecular structure with weak electronic interaction between molecules. It is desirable to have a molecular structure in which the molecular chains are not easily entangled, or to shorten the molecular chain of the specific resin.

  In addition, the specific resin used in the present invention is an amorphous resin or a semi-crystalline resin having transparency, from the viewpoint of improving the transparency of a shaped article obtained by SLS from the powder of the specific resin. preferable.

  Examples of specific resins used in the present invention that satisfy the above requirements, have excellent fluidization ability, and are suitable for SLS include the fluidization ability of the present invention (the slope of the linear function is 5.0 or more, and T is Examples include known cyclic olefin-based resins, polycarbonates, acrylic resins, and crystalline transparent resins having a characteristic that A is 1.05 or more when 1.25.

  Examples of the cyclic olefin resins include cyclic olefin ring-opening (co) polymerized hydrogenated products obtained by ring-opening (co) polymerization of norbornene-based monomers and then addition (co) polymerization of norbornene-based monomers. Addition (co) polymers, cyclic olefin copolymers obtained by copolymerizing norbornene monomers with ethylene or α-olefins, cyclic olefin addition (co) polymers obtained by addition polymerization of styrene compounds and then nuclear hydrogenation, etc. Can be mentioned.

  More specifically, specific resins used in the present invention include ARTON (manufactured by JSR Corporation), ZEONEX and ZEONOR (manufactured by ZEON Corporation), APEL (manufactured by Mitsui Chemicals, Inc.), TOPAS (polyplastic) SMMA), PMMA (polymethyl methacrylate), PC (polycarbonate) and polylactic acid, and PBT (polybutylene terephthalate).

<Additives>
Specific resins used in the present invention include antioxidants, thermal stabilizers, light stabilizers, ultraviolet absorbers, infrared absorbers, antistatic agents, dispersants, processability improvers, chlorine scavengers as necessary. Agent, flame retardant, crystallization nucleating agent, antiblocking agent, antifogging agent, mold release agent, dye, pigment, fluorescent whitening agent, organic or inorganic filler, neutralizing agent, lubricant, decomposition agent, metal inertness Known additives such as an agent, an antifouling material, an antibacterial agent and other resins, and a thermoplastic elastomer can be added as long as the effects of the present invention are not impaired. These additives may be used alone or in combination. The addition amount of the additive is usually 10 parts by mass or less with respect to 100 parts by mass of the specific resin.

  Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,2′-dioxy-3,3′-di-t-butyl-5,5′-dimethyldiphenylmethane, tetrakis [ Methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, , 3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, stearyl-β- (3,5-di-tert-butyl-4-hydroxy) Phenyl) propionate, 2,2′-dioxy-3,3′-di-t-butyl-5,5′-diethylphenylmethane, 3,9-bis [1,1-dimethyl-2- (β- (3 -T-butyl-4-hydroxy-5-methylphenyl) propio Nyloxy) ethyl], 2,4,8,10-tetraoxaspiro [5.5] undecane, tris (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,4 -Di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-t-butyl-4-methylphenyl) phosphite and 2,2-methylenebis (4,6-di-t -Butylphenyl) octyl phosphite.

  Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) ) Phenol, 2- (2H-benzotriazol-2-yl) -4,6-di-t-pentylphenol, 2-benzotriazol-2-yl 4,6-di-t-butylphenol and 2,2′- And methylenebis [4- (1,1,3,3-tetramethylbutyl) -6-[(2H-benzotriazol-2-yl) phenol]].

<Powder of specific resin used in the present invention>
Since resin powder is used in SLS, the specific resin is used in SLS in the form of resin powder.

{Method of making resin powder}
There is no restriction | limiting in particular in the method of using the said specific resin as resin powder. For example, a resin composition pellet containing a resin and a dissimilar polymer material incompatible with the resin composition are kneaded to disperse the pellet, and then the dissimilar material is dissolved in a solvent in which only the resin composition does not dissolve. Method of dissolving polymer material and recovering resin powder (Method 1), Method of spray drying resin organic solvent solution (Method 2), Recovery and drying by reprecipitation of resin organic solvent solution or emulsion The resin can be made into a resin powder by the method (Method 3), mechanical pulverization method or emulsification method.

Method 1 is disclosed in Japanese Patent Application Laid-Open No. 2007-217651. Method 2 is disclosed in JP-T-2000-504642. Method 3 is disclosed in Japanese Patent No. 3260684.
In the mechanical grinding method, resin powder is obtained by mechanically grinding the resin. The mechanical pulverization may be freeze pulverization or normal temperature pulverization. Examples of the apparatus for performing mechanical pulverization include various known apparatuses, such as a hammer mill, a jet mill, a ball mill, an impeller mill, a cutter mill, a pin mill, and a biaxial crusher. When mechanically pulverized, the resin generates frictional heat, which may cause fusion due to temperature rise, and a powder with the desired particle size may not be obtained. It is preferable to crush.

Next, the emulsification method will be described.
The emulsification method is obtained in, for example, Step 1 in which the resin is dissolved in an organic solvent, Step 2 in which the solution P obtained in Step 1 is emulsified in water or an aqueous solution Q containing a surfactant, and Step 2. And recovering the resin particles dispersed in the emulsified liquid and drying to obtain a powder. Hereinafter, each of these steps will be described.

(Process 1)
The organic solvent used in Step 1 is not particularly limited as long as it can dissolve the specific resin used in the present invention. For example, hydrocarbons such as petroleum ether, pentane, hexane, heptane, octane, nonane and decane;
Cyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, decalin, norbornane;
Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, chlorobenzene;
Halogenated hydrocarbons such as dichloromethane, dichloroethane, chlorobutane, chloroform, tetrachloroethylene;
Esters such as methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, methyl propionate;
Ethers such as dibutyl ether, tetrahydrofuran, dimethoxyethane, dioxane;
Amides such as N, N-11 dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone;
Can be mentioned. These can be used alone or in admixture of two or more.

  The concentration of the specific resin in the organic solvent solution of the specific resin used in the present invention (hereinafter also simply referred to as the solution P) is usually 5 to 40% by mass, preferably 7 to 35% by mass, and particularly preferably 10%. -30 mass%. When the concentration is less than 5% by mass, the productivity of the resin particles may be lowered, and when it exceeds 40% by mass, the dispersibility of the solution P in water or an aqueous solution Q containing a surfactant will be described later. May decrease, resulting in problems such as failure to obtain resin particles having a desired particle size.

(Process 2)
In step 2, the solution P obtained in step 1 is emulsified in water or an aqueous solution Q containing a surfactant, whereby a specific resin is dispersed in water or the aqueous solution Q to take a particle shape.

  As the stirring / dispersing means for emulsification, a conventionally known stirring device can be mentioned without particular limitation. Specific examples of such devices include impeller stirrers, sawtooth blade mixers, closed rotor mixers, rotor / stator mixers, static mixers, inline propeller / turbine mixers, inline rotor / stator mixers, colloid mills And a high-pressure homogenizer.

  Stirring conditions such as the number of revolutions of the stirrer cannot be uniquely determined because they vary depending on the equipment and the production amount of the resin particles and other conditions, but under general stirring conditions (for example, 10 to 30000 rpm) Can be implemented.

  Similarly, the stirring time cannot be determined uniquely, but it is usually 5 to 300 minutes, preferably 10 to 180 minutes, more preferably 15 to 120 minutes. If the stirring time is shorter than 5 minutes, resin dispersion may be insufficient, and resin particles having a desired particle size may not be obtained. If the stirring time is longer than 300 minutes, the productivity of resin particles decreases. Tend to.

  The temperature at which the solution P is emulsified in water or in the aqueous solution Q is usually 0 to 100 ° C, preferably 5 to 80 ° C, particularly preferably 10 to 60 ° C. If the temperature during emulsification exceeds 100 ° C., the resin particles tend to aggregate in the emulsified liquid in which the solution P is emulsified, and if it is less than 0 ° C., the production cost of the resin particles tends to increase. .

  The mass ratio (ratio of the amount used) of the solution P and water or the aqueous solution Q in the step 2 is usually [solution P] / [water or aqueous solution Q] = 1/100 to 5/1, preferably 1/50. ˜4 / 1, particularly preferably 1/30 to 3/1. If the mass ratio of the solution P and water or the aqueous solution Q is less than 1/100, the productivity of the resin particles tends to decrease, and if it is greater than 5/1, the resin particles tend to aggregate in the emulsion, which is desirable. In some cases, resin particles having a particle size of 1 mm cannot be obtained.

  As a medium for dispersing the solution P, water or an aqueous solution Q is used, and the aqueous solution Q is preferable. The presence of the surfactant increases the stability of the resin particles in the emulsion obtained in step 2.

Examples of the surfactant include known anionic surfactants such as sodium fatty acid, fatty acid potassium, sodium alkylbenzene sulfonate, sodium alkyl sulfate ester, sodium alkyl ether sulfate, sodium alpha olefin sulfonate, sodium alkyl sulfonate, and the like;
Cationic surfactants such as alkyltrimethylammonium salts and dialkyldimethylammonium salts;
Amphoteric surfactants such as sodium alkylamino fatty acids, alkylbetaines, alkylamine oxides;
Sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl ester, fatty acid alkanolamide, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxypropylene alkyl ether, polyoxypropylene fatty acid ester, etc. Of nonionic surfactants;
Etc. can be used without particular limitation.

  Specific examples of the nonionic surfactant include the Emulgen series, the Leodoll series, the Emanon series, the Leox series, the Lecole series, the Lionol series, the Leo fat made by Kao Corporation. Series, Rionon series, etc. can be listed. These may be used alone or in combination.

  The HLB value (Hydrophile-Lipophile Balance) of the surfactant is appropriately determined depending on the type of the specific resin and the organic solvent used in the present invention, but cannot be uniquely determined, but is usually 6 to 20, preferably Is 7 to 19.5, particularly preferably 7.5 to 19.

  The concentration of the surfactant in the aqueous solution Q is usually 0.1 to 20% by mass, preferably 0.2 to 18% by mass, and particularly preferably 0.3 to 15% by mass. If the concentration is less than 0.1% by mass, the stability of the resin particles in the emulsion obtained in step 2 may be insufficient. If the concentration exceeds 20% by mass, the particle diameter of the resin particles obtained is necessary. The amount of the surfactant remaining in the resin particles tends to increase with decreasing size.

(Process 3)
By collecting and drying the resin particles dispersed in the emulsion obtained in the above step 2 with a filter or mesh or the like, it is possible to obtain a powder of a specific resin used in the present invention.

  Before this recovery, the solvent R that is compatible with both the organic solvent and water used in Step 1 and does not dissolve the specific resin used in the present invention, and the emulsion obtained in Step 2 Are preferably mixed.

  Use of the solvent R is preferable because the resin particles can be solidified while maintaining a spherical shape, and the organic solvent and surfactant used for dissolving the specific resin can be extracted and removed.

The above-mentioned “does not dissolve a specific resin” specifically means that the specific resin dissolved in 100 g of the solvent R at 25 ° C. is 1 g or less.
As the solvent R satisfying such conditions, alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, and isobutanol are preferable, and methanol, ethanol, propanol, and isopropanol are particularly preferable.

The usage-amount of the solvent R is 30-2000 mass% normally with respect to 100 mass% of the said emulsion, Preferably it is 50-1000 mass%.
Further, the mixing of the solvent R and the emulsified liquid is preferably performed by stirring with a stirrer, and the stirring conditions at that time are a rotation speed of 10 to 30000 rpm, a stirring temperature of 0 to 60 ° C., and a stirring time of 5 to 120 minutes. .

  In addition, before collecting the resin particles dispersed in the emulsion obtained in Step 2 with a filter or mesh or the like, or before mixing the solvent R and the emulsion, the specific resin used in the present invention is added. You may add the process of concentrating the organic solvent used in order to make it melt | dissolve. By adding the concentration step, the amount of the organic solvent that volatilizes from the resin particles during drying is reduced, and a resin powder having a shape closer to a true sphere can be obtained.

  The pore size of the filter or mesh for recovering the above resin particles is selected according to the required particle size of the resin particles. The recovered resin particles can be made into a resin powder having a stable shape by drying with a vacuum or a hot air dryer.

  A drying temperature is 20-160 degreeC normally, Preferably it is 30-140 degreeC, More preferably, it is 40-120 degreeC. If the drying temperature is less than 20 ° C., the drying time tends to be long and the productivity tends to decrease. If the drying temperature exceeds 160 ° C., the resin particles are fused together to obtain a resin powder having a desired particle size. There may not be.

  When the particle size distribution of a specific resin powder obtained by the above-described methods (methods 1, 2, and 3, mechanical pulverization method, emulsification method) is wider than a desired distribution, classification is performed by a known classifier. May be. The classification method may be wet or dry. Specific examples of the classifier include an inertia classifier such as an air separator, a dry centrifugal classifier such as a cyclone and a micron separator, a wet centrifugal classifier such as a centrifugal sedimentator and a liquid cyclone, and a sieving machine.

{Specific resin powder}
The volume average particle diameter of the powder of the specific resin applied to the powder sintered additive manufacturing method of the present invention is preferably 1 to 200 μm, more preferably 5 to 120 μm, and more preferably 10 to 100 μm. If the volume average particle diameter is larger than 200 μm, the thickness of one layer of the cross section (slice) becomes thick at the time of modeling by the powder sintering additive manufacturing method, and the fineness of the three-dimensional model may be lacking. If the diameter is less than 1 μm, the fluidity of the particles may be insufficient or the number of slices may be too large, resulting in a lack of productivity. In the present specification, the volume average particle diameter is a volume average particle diameter measured using Nikkiso Co., Ltd. Microtrac MT3300.
Since such a resin powder is sufficiently fluidized by heating, if it is used for SLS, a molded article excellent in transparency and strength without bubbles can be provided.

<Powder sintering additive manufacturing method>
The powder sinter additive manufacturing method of the present invention is characterized by using a specific resin that satisfies the specific requirements described above (inclination in a linear function and A when T is 1.25), and particularly for its operation. There is no limit.

  As an example of the SLS of the present invention, the above-mentioned specific resin powder is spread in a thin layer, and the thin layer of the specific resin powder is fused by scanning and irradiating the thin layer with laser light. -A three-dimensional structure can be produced by sintering and sequentially laminating the sintered thin layers.

[Screening method of the present invention]
Since the present invention is a powder sintering additive manufacturing method using a specific resin powder suitable for the powder sintering additive manufacturing method, the present invention also includes a resin screening method suitable for use in the powder sintering additive manufacturing method. provide. The screening method is the ratio of the maximum projected area of the pellets before and after heating by producing the above elliptical columnar pellets from the test resin to be screened, heating them at the heating temperature t and deforming them. Whether the test resin is a resin suitable for SLS is obtained by obtaining the above linear function from the relationship between A and t and the ratio of T to the glass transition temperature of the test resin (melting point when the test resin is a crystalline resin). Judgment.

More specifically, the screening method of the present invention includes:
Step 1 for producing an elliptical columnar pellet having a major axis of an ellipse of 2 to 5 mm, a minor axis of 1 to 4 mm, and a height of 1 to 5 mm from the test resin, and a step 2 for determining the maximum projected area a1 of the pellet The pellet has a T defined by T = t / Tg (Tm) with respect to the glass transition temperature Tg (K) of the resin (melting point Tm (K) in the case of a crystalline resin) of 1.10 ≦ T Step 3 in which deformation is performed by heating for 30 minutes at a temperature t (K) in a range of ≦ 1.40 (where K represents an absolute temperature), and the maximum projected area of the pellet deformation before heating obtained in Step 3 Step 4 for obtaining a2, Step 5 for calculating the corresponding T from the temperature t, Step 6 for calculating the ratio A (a2 / a1) of a2 and a1, and Steps 1 to 6, Step 7 that is repeated twice or more and a plurality of Ts obtained from Steps 5 to 7 and each T From the relationship of A corresponding to, step 8 expressing A as a linear function of T by linear regression, and the slope of the linear function is 5.0 or more, and when T is 1.25 in the linear function, A is If it is 1.05 or more, it has a step 9 for determining that the test resin is a resin suitable for use in the powder sintering additive manufacturing method.

  In the screening method of the present invention, steps 1 to 6 performed in steps 1 to 6 and step 7 need not be performed in order from the step having the smallest number. For example, steps 2, 4, 5 and 6 may be performed after performing steps 1 and 3, and all steps 1 and 3 are performed first, including steps 1 and 3 performed in step 7. And then perform steps 2, 4, 5, and 6 for the calculation.

There is no restriction | limiting in particular in the means to manufacture an elliptic column-shaped pellet in step 1, For example, the said pellet can be manufactured with a well-known extruder.
The heating means in step 3 is not particularly limited.

  In step 7, steps 1 to 6 are repeated twice or more at different heating temperatures t. Thus, three or more A corresponding to an arbitrary T are obtained in the range of 1.10 ≦ T ≦ 1.40. In Step 7, it is sufficient to repeat Steps 1 to 6 twice, and the number of times to repeat Steps 1 to 6 is usually 10 or less.

  A resin suitable for SLS can be selected by such a screening method of the present invention, and the powder sintering additive manufacturing method of the present invention is SLS using such a selected resin. Therefore, according to the powder sinter additive manufacturing method of the present invention, the fusion between the resin powders easily proceeds and sufficiently fluidized, whereby it is possible to produce a molded article with few voids and excellent transparency. .

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

<Analysis method>
GPC: gel permeation chromatography apparatus (manufactured by Tosoh Corporation HLC-8220GPC, column: Tosoh Corp. guard column _{H XL -H, TSK gel G7000H XL} , TSK gel GMH XL 2 present, a TSK gel G2000H _XL sequentially Connection, solvent: tetrahydrofuran, flow rate: 1 mL / min, sample concentration: 0.7 to 0.8 wt%, sample injection amount: 70 μL, measurement temperature: 40 ° C., detector: RI (40 ° C.), standard substance: TSK manufactured by Tosoh Corporation Standard polystyrene) was used to measure the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn). The Mn is a number average molecular weight.

NMR: ¹ H-NMR was measured in deuterated chloroform using a superconducting nuclear magnetic resonance absorber (NMR, manufactured by Bruker, trade name: AVANCE500), and the copolymer composition ratio and hydrogenation rate of the resin were calculated. did.

Logarithmic viscosity: Using a Ubbelohde viscometer, the viscosity was measured in chloroform at a sample concentration of 0.5 g / dL and a temperature of 30 ° C.
Tg: Extrapolated glass transition temperature was determined according to Japanese Industrial Standard K7121 using a differential scanning calorimeter (trade name: DSC6220, manufactured by SII Nanotechnology).

Volume average particle diameter: Measured using Microtrack MT3300 manufactured by Nikkiso Co., Ltd.
Measurement of maximum projected area: Heating was performed using an inert oven DN6101 manufactured by Yamato Scientific under a nitrogen flow rate of 30 L / min for 30 minutes. The resin pellet before heating was in the shape of an elliptic cylinder, and the maximum projected area was set to the area of the larger one of the rectangle or ellipse in which the vertical is the height of the elliptic cylinder and the horizontal is the major axis of the ellipse. The dimensions such as the side or diameter were measured using a digital caliper, and the projected area before and after heating of at least three pellets was measured, and the average value was adopted.

[Synthesis Example 1]
As a monomer, 8-methoxycarbonyl-8-methyltetracyclo represented by the following formula (1a) [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene (100 g), 1-hexene (7.2 g) as a molecular weight regulator, and toluene (200 g) were charged into a nitrogen-substituted reaction vessel and heated to 80 ° C.

To this, 0.21 mL of a toluene solution of triethylaluminum (0.6 mol / L) and 0.86 mL of a methanol-modified WCl ₆ toluene solution (0.025 mol / L) were added and reacted at 80 ° C. for 1 hour to open the ring. A polymer was obtained.

Next, 0.04 g of chlorohydridocarbonyltris (triphenylphosphine) ruthenium (RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ ) as a hydrogenation catalyst was added to the obtained ring-opening polymer solution, The hydrogen gas pressure was 9 to 10 MPa, and the reaction was performed at a temperature of 160 to 165 ° C. for 3 hours.

After completion of the reaction, the resulting product was precipitated in a large amount of methanol to obtain a hydrogenated product [glass transition temperature (Tg) = 436 K, weight average molecular weight (Mw) = 6.7 × 10 ⁴ , molecular weight Distribution (Mw / Mn) = 5.0, logarithmic viscosity 0.45 dL / g, yield 90 g (90% yield)]. The hydrogenation rate of this hydrogenated product determined by NMR measurement was 99.0% or more. Hereinafter, the obtained ring-opening polymerization hydrogenated product is referred to as Resin 1A. Resin 1A was an amorphous resin.

［合成例２］
分子量調節剤として１−へキセン３．６ｇを用いたこと以外は合成例１と同様にして開環重合水添体を得た［ガラス転移温度（Ｔｇ）＝４４０K、重量平均分子量（Ｍｗ）＝１４．４×１０⁴、分子量分布（Ｍｗ／Ｍｎ）＝５．０、対数粘度０．７９ｄＬ／ｇ、収量９０ｇ（収率９０％）］。ＮＭＲ測定により求めたこの水添体の水素添加率は９９．０％以上であった。以後、得られた開環重合体水添体を樹脂２Ａとする。なお、樹脂２Ａは非晶性の樹脂であった。

[Synthesis Example 2]
A ring-opening polymerized hydrogenated product was obtained in the same manner as in Synthesis Example 1 except that 3.6 g of 1-hexene was used as a molecular weight regulator [glass transition temperature (Tg) = 440 K, weight average molecular weight (Mw) = 14.4 × 10 ⁴ , molecular weight distribution (Mw / Mn) = 5.0, logarithmic viscosity 0.79 dL / g, yield 90 g (yield 90%)]. The hydrogenation rate of this hydrogenated product determined by NMR measurement was 99.0% or more. Hereinafter, the obtained ring-opened polymer hydrogenated product is referred to as Resin 2A. Resin 2A was an amorphous resin.

[Synthesis Example 3]
133.5 g of the monomer represented by the formula (1a), 16.5 g of the monomer represented by the following formula (2a), 19.8 g of 1-hexene as a molecular weight regulator, and 225 g of toluene were replaced with nitrogen. The reaction vessel was charged and heated to 80 ° C.

To this was added 0.34 mL of a toluene solution of triethylaluminum (0.6 mol / L) and 1.37 mL of a methanol-modified WCl ₆ toluene solution (0.025 mol / L), and the mixture was reacted at 80 ° C. for 1 hour to open the ring. A copolymer was obtained.

Next, 0.06 g of chlorohydridocarbonyltris (triphenylphosphine) ruthenium (RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ ) as a hydrogenation catalyst was added to the obtained ring-opening copolymer solution. The hydrogen gas pressure was 9 to 10 MPa, and the reaction was performed at a temperature of 160 to 165 ° C. for 3 hours.

After completion of the reaction, the resulting product was precipitated in a large amount of methanol to obtain a hydrogenated product [glass transition temperature (Tg) = 399 K, weight average molecular weight (Mw) = 5.0 × 10 ⁴ , molecular weight Distribution (Mw / Mn) = 4.2, logarithmic viscosity 0.43 dL / g, yield 90 g (90% yield)]. The hydrogenation rate of this hydrogenated product determined by NMR measurement is 99.0% or more, and the copolymer composition ratio is [structure derived from (1a)] / [structure derived from (2a)] = 89/11 (weight) Ratio). Hereinafter, the obtained ring-opening copolymer hydrogenated product is referred to as Resin 1B. Resin 1B was an amorphous resin.

[合成例４]
分子量調節剤として１−へキセン１３．６ｇを用いたこと以外は合成例３と同様にして開環共重合水添体を得た［ガラス転移温度（Ｔｇ）＝４０３K、重量平均分子量（Ｍｗ）＝６．８×１０⁴、分子量分布（Ｍｗ／Ｍｎ）＝５．０、対数粘度０．５３ｄＬ／ｇ、収量９０ｇ（収率９０％）］。共重合組成比は[(1a)由来の構造]/[(2a)由来の構造]=（８９/１１）（重量比）であった。以後、得られた開環共重合水添体を樹脂２Ｂとする。なお、樹脂２Ｂは非晶性の樹脂であった。

[Synthesis Example 4]
A ring-opening copolymerized hydrogenated product was obtained in the same manner as in Synthesis Example 3 except that 13.6 g of 1-hexene was used as a molecular weight regulator [glass transition temperature (Tg) = 403K, weight average molecular weight (Mw) = 6.8 × 10 ⁴ , molecular weight distribution (Mw / Mn) = 5.0, logarithmic viscosity 0.53 dL / g, yield 90 g (yield 90%)]. The copolymer composition ratio was [structure derived from (1a)] / [structure derived from (2a)] = (89/11) (weight ratio). Hereinafter, the obtained ring-opening copolymerized hydrogenated product is referred to as Resin 2B. Resin 2B was an amorphous resin.

[Synthesis Example 5]
113.2 g of the monomer represented by the formula (1a), 1.5 g of the monomer represented by the formula (2a), 35.3 g of the monomer represented by the following formula (3a), molecular weight adjustment As a chemical, 20.4 g of 1-hexene and 225 g of toluene were charged into a reaction vessel purged with nitrogen, and heated to 80 ° C.

To this was added 0.34 mL of a toluene solution of triethylaluminum (0.6 mol / L) and 1.39 mL of a methanol-modified WCl ₆ toluene solution (0.025 mol / L), and the mixture was allowed to react at 80 ° C. for 1 hour to open the ring. A copolymer was obtained.

Next, (4-pentylbenzoyloxy) carbonyl (hydrido) bis (triphenylphosphine) ruthenium {RuH (OCO—Ar—CH ₂ CH ₂ CH ₂ ) as a hydrogenation reaction catalyst is added to the obtained ring-opening copolymer solution. 0.06 g of CH ₂ CH ₃ ) (CO) [P (C ₆ H ₅ ) ₃ ] ₂ (wherein Ar represents a paraphenylene group)} is added, the temperature is raised to 90 ° C., and then the hydrogen gas pressure is increased. The pressure was 9 to 10 MPa, and the temperature was further raised to 160 to 165 ° C. to react for 3 hours.

After completion of the reaction, the resulting product was precipitated in a large amount of methanol to obtain a hydrogenated product [glass transition temperature (Tg) = 410 K, weight average molecular weight (Mw) = 3.8 × 10 ⁴ , molecular weight Distribution (Mw / Mn) = 5.1, logarithmic viscosity 0.36 dL / g, yield 90 g (90% yield)]. The hydrogenation rate of this hydrogenated product obtained by NMR measurement is 99.0% or more, and the copolymer composition ratio is [structure derived from (1a)] / [structure derived from (2a)] / [derived from (3a) Of structure] = 75.3 / 23.6 / 1.1 (weight ratio). Hereinafter, the obtained hydrogenated ring-opening copolymer is referred to as Resin 1C. Resin 1C was an amorphous resin.

[合成例６]
分子量調節剤として１−へキセン７．６ｇを用いたこと以外は合成例５と同様にして開環共重合水添体を得た［ガラス転移温度（Ｔｇ）＝４１７K、重量平均分子量（Ｍｗ）＝９．４×１０⁴、分子量分布（Ｍｗ／Ｍｎ）＝５．０、対数粘度０．６４ｄＬ／ｇ、収量９０ｇ（収率９０％）］。共重合組成比は[(1a)由来の構造]/[(2a)由来の構造]/[(3a)由来の構造]=（75.5/23.5/1.0）（重量比）であった。ＮＭＲ測定により求めたこの水素添加物の水素添加率は９９．０％以上であった。以後、得られた開環共重合水添体を樹脂２Ｃとする。なお、樹脂２Ｃは非晶性の樹脂であった。

[Synthesis Example 6]
A ring-opening copolymerized hydrogenated product was obtained in the same manner as in Synthesis Example 5 except that 7.6 g of 1-hexene was used as a molecular weight regulator [glass transition temperature (Tg) = 417 K, weight average molecular weight (Mw) = 9.4 × 10 ⁴ , molecular weight distribution (Mw / Mn) = 5.0, logarithmic viscosity 0.64 dL / g, yield 90 g (yield 90%)]. The copolymer composition ratio was [structure derived from (1a)] / [structure derived from (2a)] / [structure derived from (3a)] = (75.5 / 23.5 / 1.0) (weight ratio). The hydrogenation rate of this hydrogenated product determined by NMR measurement was 99.0% or more. Hereinafter, the obtained ring-opening copolymerized hydrogenated product is referred to as Resin 2C. Resin 2C was an amorphous resin.

[Example 1]
The resin 1A obtained in Synthesis Example 1 (glass transition temperature: 436 K) was melted using a biaxial extruder (TEM-37BS, manufactured by Toshiba Machine) to obtain a pellet-shaped polymer. The cylinder temperature was 280 ° C., the shaft rotation speed was 100 rpm, and the extrusion speed was 10 to 20 kg / hr. The appearance of the obtained pellet was transparent and had an elliptical columnar shape. The dimensions of the pellets before heating are: ellipse major axis = 2.96 mm, ellipse minor axis = 2.77 mm, elliptical column height = 3.07 mm, and the projected shape of the elliptical column viewed from directly above the elliptical cross section is Since it is an ellipse, the projected area is the area of the ellipse = (2.96 / 2) × (2.77 / 2) × π = 6.44 mm ² . On the other hand, when the side column part of the elliptical column is viewed from directly above, the projected shape is a rectangle composed of the major axis of the ellipse and the height of the elliptical column, and in this case, the projected area is 2.96 × 3.07 = 9.09 mm ² . Therefore, the maximum projected area a1 of this pellet is 9.09 mm ² . The maximum projected area of the pre-heating pellet thus obtained was as shown in Table 1 below.

このペレットをオーブンを用いて５１３K（T＝５１３K／４３６K＝１．１８）、５３３K（T＝１．２２）または５５３K（T＝１．２７）で30分間加熱したところ、ペレットは楕円板の形状に変形した。513Kの加熱を受けたペレットは長径=3.82mm、短径=3.21mmの楕円板に変形したため、この楕円板状樹脂の投影面積ａ２は(3.82／2)×(3.21／2)×π=9.63mm²であった。従ってＡ＝ａ２／ａ１＝１．０６である。同様にして３粒のペレットを評価してその平均値を算出すると１点目のデータ（Ｔ，Ａ）=（1.18, 1.07）が得られた。同様にして加熱後の楕円の長径および短径、投影面積を求めたところ上記表１の通りであった。５３３K、５５３Kで加熱したペレットについても同様にして、（Ｔ，Ａ）を求めた。結果は表１に示されている。

This pellet was heated in an oven at 513K (T = 513K / 436K = 1.18), 533K (T = 1.22) or 553K (T = 1.27) for 30 minutes. Transformed into. Since the pellets heated at 513K were deformed into an elliptical plate with a major axis = 3.82mm and a minor axis = 3.21mm, the projected area a2 of this elliptical resin was (3.82 / 2) × (3.21 / 2) × π = 9.63 mm ² . Therefore, A = a2 / a1 = 1.06. Similarly, when three pellets were evaluated and the average value was calculated, the first data (T, A) = (1.18, 1.07) was obtained. Similarly, the major axis and minor axis of the ellipse after heating and the projected area were determined as shown in Table 1 above. Similarly, (T, A) was obtained for pellets heated at 533K and 553K. The results are shown in Table 1.

From the above results, the relationship between T and A (a2 / a1) is (T, A) = (1.18, 1.07), (1.22, 1.26), (1.27, 1.83). The data was obtained. When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 8.28T−8.78 (correlation coefficient r = 0.96)
In the linear function, the A value at T = 1.25 is 1.570.

  This resin (resin 1A) was pulverized to a volume average particle size of 49 μm by a freeze pulverizer, and the obtained powder was put into a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes, and a powder fusing property appearance test was performed. The result was transparent.

  In this test, the powder melted and spread with heat only under the load of the powder's own weight, and a uniform and transparent fused body could be formed by fusing with other powder. Therefore, if the resin powder used in this test is used for SLS, an integrally shaped object having an arbitrary shape can be obtained without defects based on bubbles and non-uniformity.

[Example 2]
Pellets were prepared in the same manner as in Example 1 except that the resin 1B obtained in Synthesis Example 3 (glass transition temperature is 399 K) was used. The pellets were heated and deformed using an oven at 514 K, 534 K, and 554 K before and after heating. The maximum projected area of the pellet was determined, and data (T, A) = (1.29, 1.54), (1.34, 1.94), (1.39, 2.22) were obtained (see Table 2 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 6.70T−7.07 (correlation coefficient r = 0.99)

前記一次関数において、T=1.25におけるA値は１．２９５である。

In the linear function, the A value at T = 1.25 is 1.295.

  After the resin was pulverized to a volume average particle size of 46 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Example 3]
Pellets were prepared in the same manner as in Example 1 except that the resin 1C obtained in Synthesis Example 5 (glass transition temperature is 410K) was used. The pellets were heated and deformed using an oven at 514K, 534K, and 554K before and after heating. The maximum projected area of the pellet was determined, and data (T, A) = (1.25, 1.87), (1.30, 2.40), (1.35, 2.69) were obtained (see Table 3 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 8.38T-8.59 (correlation coefficient r = 0.99)

前記一次関数において、T=1.25におけるA値は1.885である。

In the linear function, the A value at T = 1.25 is 1.885.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Example 4]
Prepare pellets in the same manner as in Example 1 except that ZEONEX 480R (glass transition temperature is 412K) manufactured by Nippon Zeon Co., Ltd. is heated and deformed using an oven at 513K, 533K, and 553K before and after heating. The maximum projected area of the pellets was determined, and data (T, A) = (1.24, 1.13), (1.29, 1.59), (1.34, 2.03) were obtained (see Table 4 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 9.32T-10.46 (correlation coefficient r = 0.99)

前記一次関数において、T=1.25におけるA値は１．１９０である。

In the linear function, the A value at T = 1.25 is 1.190.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Example 5]
Prepare pellets in the same manner as in Example 1 except that ZEONEX E48R (glass transition temperature 413K) manufactured by Nippon Zeon Co., Ltd. was used, and heated and deformed using an oven at 513K, 533K, and 553K before and after heating. The maximum projected area of the pellets was determined, and data (T, A) = (1.24, 1.20), (1.29, 1.56), (1.34, 1.97) were obtained. (See Table 5 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 7.95T−8.68 (correlation coefficient r = 1.00)

前記一次関数において、T=1.25におけるA値は１．２５８である。

In the linear function, the A value at T = 1.25 is 1.258.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Example 6]
Prepare pellets in the same manner as in Example 1 except that ZEONEX 330R (glass transition temperature 399K) manufactured by Nippon Zeon Co., Ltd. was used, and heated and deformed using an oven at 497K, 513K, and 553K before and after heating. The maximum projected area of the pellet was determined, and data (T, A) = (1.25, 1.07), (1.29, 1.84), (1.39, 3.07) were obtained. (See Table 6 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 13.86T-16.12 (correlation coefficient r = 0.99)

前記一次関数において、T=1.25におけるA値は１．２０５である。

In the linear function, the A value at T = 1.25 is 1.205.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Example 7]
Except that ZEONEX 340R (glass transition temperature is 397K) manufactured by Nippon Zeon Co., Ltd. was used, pellets were prepared in the same manner as in Example 1, and heated and deformed at 497K, 513K, 533K using an oven before and after heating. The maximum projected area of the pellets was determined, and data of (T, A) = (1.25, 1.07), (1.29, 2.00), (1.34, 3.01) were obtained. (See Table 7 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 21.28T-25.55 (correlation coefficient r = 1.00)

前記一次関数において、T=1.25におけるA値は１．０５０である。

In the linear function, the A value at T = 1.25 is 1.050.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Example 8]
Pellets were prepared in the same manner as in Example 1 except that ZEONOR 1420R (glass transition temperature 412K) manufactured by Nippon Zeon Co., Ltd. was used, and heated and deformed using an oven at 497K, 513K, and 533K before and after heating. The maximum projected area of the pellets was determined, and data (T, A) = (1.21, 1.02), (1.25, 1.29), (1.29, 1.56) were obtained. (See Table 8 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 6.17T-6.41 (correlation coefficient r = 1.00)

前記一次関数において、T=1.25におけるA値は１．３０３である。

In the linear function, the A value at T = 1.25 is 1.303.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Example 9]
Pellets were prepared in the same manner as in Example 1 except that APEL 5014DP (glass transition temperature: 408K) manufactured by Mitsui Chemicals, Inc. was used, heated and deformed using an oven at 513K, 533K, and 553K before and after heating. The maximum projected area of the pellets was determined, and data (T, A) = (1.26, 1.82), (1.31, 2.21), (1.36, 2.61) were obtained (see Table 9 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 8.10T−8.37 (correlation coefficient r = 1.00)

前記一次関数において、T=1.25におけるA値は１．７５５である。

In the linear function, the A value at T = 1.25 is 1.755.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Example 10]
Pellets were prepared in the same manner as in Example 1 except that Panlite AD5503 (glass transition temperature: 417K) manufactured by Teijin Chemicals Ltd. was used, and the pellets were heated at 513K, 533K, and 553K using an oven and deformed and heated. The maximum projected areas of the front and rear pellets were determined, and data (T, A) = (1.23,3.66), (1.28,3.90), (1.33,4.14) were obtained (see Table 10 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 5.00T-2.49 (correlation coefficient r = 1.00)

前記一次関数において、T=1.25におけるA値は3.760である。

In the linear function, the A value at T = 1.25 is 3.760.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. It was.

[Comparative Example 1]
Pellets were prepared in the same manner as in Example 1 except that the resin 2A obtained in Synthesis Example 2 (glass transition temperature: 440 K) was used, and heated and deformed using an oven at 515 K, 535 K, and 555 K before and after heating. The maximum projected area of the pellet was determined, and data (T, A) = (1.17,0.89), (1.22, 1.00), (1.26, 1.10) were obtained (see Table 11 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 2.30T-1.80 (correlation coefficient r = 1.00)

前記一次関数において、T=1.25におけるA値は１．０７５である。

In the linear function, the A value at T = 1.25 is 1.075.

  After the resin was pulverized to a volume average particle size of 50 μm by a freeze pulverizer, the obtained powder was put into a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes, and a powder fusing property appearance test was conducted. It contained bubbles and was cloudy.

[Comparative Example 2]
A pellet was prepared and deformed in the same manner as in Example 1 except that the resin 2B obtained in Synthesis Example 4 (glass transition temperature is 403K) was used to determine the maximum projected area before and after heating, and 515K and 535K using an oven. The maximum projected area of the pellet before and after heating was calculated by heating at 555K and deformed, and the following data were obtained: (T, A) = (1.28,1.09), (1.33, 1.34), (1.38, 1.59) (See Table 12). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 5.00T-5.30 (correlation coefficient r = 1.00)

前記一次関数において、T=1.25におけるA値は0.950である。

In the linear function, the A value at T = 1.25 is 0.950.

  After the resin was pulverized to a volume average particle size of 49 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes. However, it contained a large number of bubbles and was cloudy.

[Comparative Example 3]
Pellets were prepared in the same manner as in Example 1 except that the resin 2C obtained in Synthesis Example 6 was used, and heated and deformed using an oven at 515K, 535K, and 555K to obtain the maximum projected area of the pellets before and after heating. , (T, A) = (1.24, 1.00), (1.28, 1.20), (1.33, 1.39) were obtained (see Table 13 below). When this was linearly regressed by the least square method, the obtained linear function was as follows.
A = 3.90T-3.80 (correlation coefficient r = 1.00)

前記一次関数において、T=1.25におけるA値は１．０７５である。

In the linear function, the A value at T = 1.25 is 1.075.

After the resin was pulverized to a volume average particle size of 47 μm by a freeze pulverizer, the obtained powder was put in a glass bottle and heat-treated at a temperature of Tg + 70 ° C. for 30 minutes, and as a result of a powder fusing property appearance test, transparency However, it contained a large number of bubbles and was cloudy.
The above results are summarized in Table 14 below.

以上の結果から、１．１０≦Ｔ≦１．４０の範囲において、任意のTに対応するAの値のデータから直線回帰によりAをTの一次関数として表した場合に、該一次関数の傾きが５．０以上であり、かつ該一次関数においてTが１．２５のときにAが１．０５以上である樹脂から得られる粉末の流動化能力が優れていることが判明した。このような樹脂を用いたSLSにより、透明性および強度に優れた造形物が得られることが期待される。

From the above results, when A is represented as a linear function of T by linear regression from A value data corresponding to an arbitrary T in the range of 1.10 ≦ T ≦ 1.40, the slope of the linear function Was found to be excellent in fluidization ability of a powder obtained from a resin having A of 1.05 or more when T is 1.25 in the linear function. It is expected that a molded article having excellent transparency and strength can be obtained by SLS using such a resin.

Claims (6)

A powder sintering additive manufacturing method using a specific resin powder,
The specific resin is
The resin is an elliptical columnar pellet having an elliptical major axis of 2 to 5 mm, a minor axis of 1 to 4 mm, and a height of 1 to 5 mm,
The pellet has a T defined by T = t / Tg (Tm) with respect to the glass transition temperature Tg (K) of the resin (melting point Tm (K) in the case of a crystalline resin) of 1.10 ≦ T ≦ 1. The maximum projected area of a product obtained by deforming a pellet before heating obtained by heating at a temperature t (K) in the range of 1.40 for 30 minutes is defined as a2 (K represents an absolute temperature). The maximum projected area is a1, the ratio of a2 to a1 (a2 / a1) is A,
1. In the range of 10 ≦ T ≦ 1.40, obtain three or more values of A corresponding to any T, and express A as a linear function of T by linear regression from the relationship between A and T obtained In addition, a powder firing using a specific resin powder is characterized in that the slope of the linear function is 5.0 or more, and A is 1.05 or more when T is 1.25 in the linear function. Bonding modeling method.   The powder sintering additive manufacturing method according to claim 1, wherein the specific resin is an amorphous resin or a semi-crystalline resin having transparency.   The powder sintered additive manufacturing method according to claim 1 or 2, wherein the glass transition temperature (melting point in the case of a crystalline resin) of the specific resin is 100 to 200 ° C.   The powder sintered additive manufacturing method according to any one of claims 1 to 3, wherein the volume average particle diameter of the powder of the specific resin is 1 to 200 µm.   A shaped article obtained by shaping by the powder sintering layered shaping method according to claim 1. A resin screening method suitable for use in a powder sintering additive manufacturing method,
Step 1 of producing an elliptical columnar pellet having a major axis of an ellipse of 2 to 5 mm, a minor axis of 1 to 4 mm, and a height of 1 to 5 mm from the test resin;
Determining the maximum projected area a1 of the pellet;
The pellet has a T defined by T = t / Tg (Tm) with respect to the glass transition temperature Tg (K) of the resin (melting point Tm (K) in the case of a crystalline resin) of 1.10 ≦ T ≦ Step 3 (K represents an absolute temperature), which is deformed by heating for 30 minutes at a temperature t (K) in the range of 1.40,
Step 4 for obtaining the maximum projected area a2 of the deformation of the pellet before heating obtained in Step 3;
Calculating a corresponding T from the temperature t;
Step 6 for calculating a ratio A (a2 / a1) of a2 and a1;
Steps 7 to 6 are repeated twice or more by changing the temperature t, and
Step 8 expressing A as a linear function of T by linear regression from the relationship between the plurality of T obtained from Steps 5 to 7 and A corresponding to each T;
When the slope of the linear function is 5.0 or more and A is 1.05 or more when T is 1.25 in the linear function, the test resin is used in the powder sintering additive manufacturing method. And a step 9 for determining that the resin is suitable for the resin. A resin screening method suitable for use in the powder sintering additive manufacturing method.