US20070204967A1 - Method of Smoothing Surface and Process of Lost Wax Precious Casting with Resin Model Having Its Surface Smoothing by the Method - Google Patents

Method of Smoothing Surface and Process of Lost Wax Precious Casting with Resin Model Having Its Surface Smoothing by the Method Download PDF

Info

Publication number
US20070204967A1
US20070204967A1 US10/586,638 US58663804A US2007204967A1 US 20070204967 A1 US20070204967 A1 US 20070204967A1 US 58663804 A US58663804 A US 58663804A US 2007204967 A1 US2007204967 A1 US 2007204967A1
Authority
US
United States
Prior art keywords
model
powder
type urethane
reaction hardening
hardening type
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/586,638
Other languages
English (en)
Inventor
Taro Kita
Kazuki Kamata
Minoru Matsumura
Akio Saito
Masato Kikuchihara
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shonan Design Co Ltd
Original Assignee
Shonan Design Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shonan Design Co Ltd filed Critical Shonan Design Co Ltd
Assigned to SHONAN DESIGN CO., LTD. reassignment SHONAN DESIGN CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KAMATA, KAZUKI, KIKUCHIHARA, MASATO, KITA, TARO, MATSUMURA, MINORU, SAITO, AKIO
Publication of US20070204967A1 publication Critical patent/US20070204967A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
    • B29C41/20—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles incorporating preformed parts or layers, e.g. moulding inserts or for coating articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C7/00—Patterns; Manufacture thereof so far as not provided for in other classes
    • B22C7/02—Lost patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B22C9/04—Use of lost patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/10—Cores; Manufacture or installation of cores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
    • B29C41/14—Dipping a core
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0037—Other properties
    • B29K2995/0072—Roughness, e.g. anti-slip
    • B29K2995/0073—Roughness, e.g. anti-slip smooth
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • the present invention relates to a method for smoothing a surface of a powder-sintered laminated resin model (A) with a porous rough surface fabricated according to sintering/laminating shaping technique.
  • A powder-sintered laminated resin model
  • a porous rough surface fabricated according to sintering/laminating shaping technique a surface of a model obtained by burning and laminating impalpable powder of resin is made smooth by radiating a carbon dioxide gas laser beam controlled by a computer to it, the resulting model is adapted to a lost wax precision casting as an alternative model of a wax model.
  • the lost wax process casting includes manufacturing steps in which; a wax model achieving a shape identical to the shape of a cast product is manufactured by pouring a melted wax component into a die, cooling the wax component and then disengaging the wax from the die; a hollow casting mold is manufactured by coating the surface of the wax model with a refractory material, heating the wax model to cause the wax model to melt and flow out and then burning off the wax through high temperature baking; and a molten alloy is poured into the hollow casting mold, after which the alloy is cooled and set and the cast product is taken out by splitting off the casting mold.
  • Model material used in the lost wax precision casting method is generally a wax component. Numerous research and development efforts about the model material are performed.
  • the wax component constituting wax models used in the lost wax process is normally a blend of paraffin, rosin, carnauba wax and terephthlalic acid. Possible compositions that may be adopted for the wax component are described in detail in Casting Guidebook (edited by the Japanese Casters Association). In addition, the efficacy of a wax component containing melamine particles blended therein has been reported in recent years (see Japanese Unexamined Patent Publication No. H5-38549).
  • H7-9084 discloses a model achieved by laminating a lost wax base on a photohardening resin sheet.
  • Japanese Unexamined Patent Publication No. H7-299542 discloses a model achieved by applying a wax plastic material onto an ornamental model with fine features constituted of cotton yarn and a synthetic material.
  • Japanese Unexamined Patent Publication No. H7-47443 discloses a model achieved by inserting a photohardening resin model or heat meltable resin laminated model into a die and injection-molding wax.
  • Japanese Unexamined Patent Publication No. 2000-263186 discloses a model achieved by laminating a lost wax base on an ultraviolet hardening resin model.
  • the optical molding method is that ultraviolet rays controlled by a computer are emitted to photo-setting type resin solution to be hardened in doughnut disc shape in turn so as to be laminated in order to obtain a cubic molding.
  • the powder-sintered laminated molding method is that carbon dioxide gas laser beams controlled by a computer are emitted to impalpable powder of resin to melt, fuse and laminate it for molding.
  • the most popular solid surface smoothing method is to apply coating to the solid surface.
  • Three purposes of the painting are to protect a foundation, to give a fine spectacle and to give enhance of consciousness. Smoothing of a surface is present in giving of a surface property. Thickness of coating is usually 10-30 ⁇ m at the most and 100-200 ⁇ m in a thick coating, so that surface smoothing is performed in thus thickness range.
  • the foundation has larger roughness than the above range, it is necessary to level the roughness or unevenness by applying putty.
  • a main purpose of applying putty is smoothing of the surface, it is general to paint after sandpapering the dry hardened putty surface.
  • an effect of smoothing surface can be produced.
  • Putting up of hanging paper, putting up of decorative film or the like aims at protection or design similarly to painting.
  • resin solution impregnates from the surface of the solid into the porous portions inside the solid to effect increasing of strength, increasing of durability and a special surface property while the surface smoothing is given.
  • EOS discloses a working mode so as to apply a wax component to a surface of the model, but there is no method which has been reported yet.
  • the model for the lost wax precision casting produced in the process of the powder-sintered laminated casting is that particles whose particle size is 60-80 ⁇ m are in a condition of fusing partly due to surface melting by emitting carbon oxide laser beams controlled by a computer to resin powder, and because the lamination pitch is 0.05-0.2 mm, it is confirmed visually that roughness of the surface is confirmed visibly and it is confirmed clearly in touch that the rough surface where the particles are arranged successively.
  • the powder-sintered laminated model is adapted to the lost wax precision casting, because the roughness surface of the model is traced to the inner surface of the mold and the inner surface of the mold is traced to the surface of the molding article, a smooth surface, a sharpen edge and a smooth curved surface of the molding article is difficult to be achieved, so that the molding article is far from a visually superior molding article.
  • a big default of the powder-sintered laminated casting process is that lamination pitches appear on the model surface, that steps are produced on a curved surface because of stepped lamination and that a smooth surface, a smooth curved surface and a sharpen edge are difficult to be achieved because traces of the particle size are remained on the surface due to melting and fusing fine particles.
  • the powder-sintered laminated resin model made of powdery resin and produced in the sintered and laminated layer casting process is adapted to the lost wax precision casting, a finished surface of the molding article is rough, so that commercial value of it is decreased largely.
  • the surface of the powder-sintered laminated resin model must be improved so as to be smooth.
  • a method for smoothing a surface of a powder-sintered laminated resin model with a porous rough surface comprises a resin impregnation step of dipping the powder-sintered laminated resin model (A) in a two-pack reaction hardening type urethane resin solution (B) with a work life of 1 to 5 minutes and viscosity of 7 to 30 Pas and then decreasing pressure so as to impregnate the surface of the resin model (A) with the two-pack reaction hardening type urethane resin solution (B); and a resin hardening step of bringing up the powder-sintered laminated resin model (A) impregnated with the two-pack reaction hardening type urethane resin solution (B) from the two-pack reaction hardening type urethane resin solution (B) and hardening the resin model (A).
  • the two-pack reaction hardening type urethane resin solution (A) preferably comprises multifunctional polyol component (a), multifunctional polyisocyanate component (b) and a plasticizer component (c), and an average functional group of the multifunctional polyol component (a) is preferably in a range from 2.0 to 4.0, an average functional group of the multifunctional polyisocyanate component (b) is preferably in a range from 3.0 to 5.0, and a ratio NCO/OH is preferably in a range from 0.7 to 1.0.
  • the two-pack reaction hardening type urethane resin solution (A) preferably contains a plasticizer component (c) of 10-30% which is in a liquid state at normal temperature and polyether chains having a chemical structure indicated in the chemical structural formula as follows at 5-35 wt % thereof.
  • plasticizer component (c) is preferably micro-dispersed through phase separation at raid reaction hardening of the two-pack reaction hardening type urethane resin solution (B).
  • the powder-sintered laminated resin model having a surface smoothed by the present invention is used in the lost wax precision casting method.
  • FIG. 1 is a plan view showing one example of a resin model
  • FIG. 2 is a partly enlarged section view enlarging a part of the resin model shown in FIG. 1 ;
  • FIG. 3 is an enlarged section view further enlarging a part shown in FIG. 2 ;
  • FIG. 4 is an explanatory diagram illustrating a resin impregnation step
  • FIG. 5 is an explanatory diagram illustrating a resin hardening step
  • FIG. 6 is a partly enlarged section view of the resin model after the resin hardening step.
  • FIGS. 1 to 6 shows processes for performing surface smoothing of a sintered and laminated resin model (hereinafter, resin model) according to a working mode of the present invention.
  • resin model sintered and laminated resin model
  • FIG. 1 shows a resin model (A) for an automobile handle as one example of the sintered and laminated resin model.
  • This is a resin model formed by sintering and laminating polystyrene powder.
  • FIG. 2 shows an enlarged part of an outer circumferential portion of the resin model (A) of the automobile handle.
  • FIG. 3 shows further enlargement of the part shown in FIG. 2 .
  • fused fine powder polystyrene particles C are laminated at lamination pitch H like stairs.
  • FIG. 4 shows that: the resin model (A) shown in FIG. 1 is impregnated with two-pack reaction hardening type urethane resin solution (B) with a work life of 1 to 5 minutes and viscosity of not more than 30 Pas in a container (D), a decompression valve (E) is opened and a vacuum pump (G) is operated so as to decrease pressure.
  • a decompression valve (E) is opened and a vacuum pump (G) is operated so as to decrease pressure.
  • the air of hollow parts (I) ( FIG. 3 ) communicating to an outside is discharged from a surface of the resin model (A) as bubbles (F), so that the two-pack reaction hardening type urethane resin solution (B) impregnates into the hollow parts (I).
  • a mark (J) indicates a pressure gauge.
  • FIG. 5 shows that the resin model is brought up form the container (D) of the two-pack reaction hardening type urethane resin solution (B) and that the rest of the two-pack reaction hardening type urethane resin solution (B) is fallen down from the resin model (A) as drops (K).
  • the two-pack reaction hardening type urethane resin solution (B) impregnated in the resin starts to be hardened, so that it becomes tack-free 5 to 30 minutes later and it is hardened.
  • the above mentioned is a resin hardening step.
  • the mark (L) indicates a cover portion.
  • FIG. 6 shows enlargement of circumferential portion of the resin model (A) after the resin hardening step. It shows that the resin solution (B) is stuck and hardened on surfaces of layers of polystyrene particles (C) laminated like stairs and it results that stairs-like surface M is changed to a circumferential surface N. Namely, it shows that a uneven surface shown in FIG. 2 has been smoothed.
  • the two-pack reaction hardening type urethane resin solution (B) consists of two components such as a polyisocyanate component (a) and a polyol component (b).
  • the polyisocyanate component (a) is a compound containing at least two isocyanate groups in a single molecule.
  • the isocyanate groups which are functional groups with an extremely high level of reactivity, react with hydroxyl groups containing active hydrogen, amino groups and thiol groups. Since isocyanate groups generally react with amino groups and thiol groups instantaneously, they are normally used only in combination with a less reactive isocyanate component or less reactive aromatic amines, but they still react fairly quickly and for this reason, such a combination is not commonly used.
  • the polyisocyanate component (a) may be constituted with an aromatic polyisocyanate, an aliphatic polyisocyanate, or an alicyclic isocyanate.
  • aromatic polyisocyanate include tolylenediisocyanate and diphenylmethane diisocyanate.
  • tolylenediisocyanate is obtained as a mixture of various isomers, and various industrial products with varying mixing ratios of the 2,4-body and the 2,6-body, e.g., TDI-100 (2,4-TDI 100%), TDI-80 (2,4-TDI 80%, 2,6-TDI 20%) and TDI-65 (2,4-TDI 65%, 2,6-TDI 35%), are commercially available.
  • diphenylmethane diisocyanate is obtained as a mixture of various isomers, and is used in the form of either pure MDI or polymeric MDI in industrial applications.
  • the pure MDI is a dicaryonic, whereas the polymeric MDI is a multicaryonic. While the pure MDI is isolated through distillation, the polymeric MDI is obtained as residue. Since the number of multicaryons in the polymeric MDI changes under different manufacturing conditions, various types of polymeric MDI are produced and are offered as commercial products by numerous manufacturers.
  • aromatic polyisocyanates include napthalene diisocyanate achieved by adding an isocyanate group to a napthalene nucleus and tolidine diisocyanate.
  • aliphatic polyisocyanate examples include hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate and lysine diisocyanate.
  • the alicyclic polyisocyanate may be hydrogenated xylene diisocyanate obtained by hydrogenating xylene diisocyanate or hydrogenated MDI obtained by hydrogenating MDI.
  • polyisocyanate components are highly reactive and, in particular, volatile polyisocyanate components are highly toxic. For this reason, they are normally used after undergoing various types of metamorphisms.
  • a metamorphism may be urethane modification, dimerization, trimerization, polycarbonimidization, urea modification, pre-polymerization and blocking.
  • self condensation is induced by taking advantage of the higher reactivity of the isocyanate groups, or the isocyanate groups are joined via an active component while leaving a terminal isocyanate group.
  • the multifunctional polyol component (b) may be a low molecular polyol, a polyether a polyol, an amine polyol, a polyester polyol, an acrylic polyol or a polybutadiene polyol.
  • castor oil and its derivatives may also be used to constitute the multifunctional polyol component (b).
  • low molecular polyol examples include ethylene glycol, propylene glycol, 1-4 butanediol, glycerine, trimethyl propane, and pentaerythritol.
  • the polyether polyol may be a polyether polyol achieving a specific molecular weight obtained by adding ethylene oxide or propylene oxide into the low molecular polyol.
  • a primary or secondary terminal hydroxyl group can be achieved in the polyether polyol by blending an additional constituent in a specific manner, e.g., by adding ethylene oxide by itself, adding propylene oxide by itself, adding a mixture of ethylene oxide and propylene oxide or adding ethylene oxide and propylene oxide separately in sequence.
  • Various types of polyether polyols with ethylene oxide and propylene oxide rendering diverse hydrophilic/hydrophobic properties in their additional chains can be achieved by varying the reactivity of the hydroxyl group terminal through the different blending methods. These come onto the market.
  • An amine polyol is a substance achieved by adding ethylene oxide or propylene oxide to a low molecular amine such as ammonia, ethylene diamine or polyethylene polyamine.
  • a low molecular amine such as ammonia, ethylene diamine or polyethylene polyamine.
  • the amine polyol which contains tertiary nitrogen within its molecule, is a polyol retaining an effect of promoting the reaction of isocyanate. This component is indispensable to the present invention in which rapid hardening is performed.
  • the polyester polyol (b) may be a condensed polyester polyol having a hydroxyl group constituting a molecular terminal achieved by esterifying a dibasic acid and a low molecular polyol.
  • dibasic acid and low molecular diol triol By selecting specific types of dibasic acid and low molecular diol triol, adjusting the molecular weight and using a small quantity of a multifunctional low molecular polyol, diverse types of polyester polyols can be prepared.
  • polyester polyol having polyester chains and polyether chains can be made, so that they are very various.
  • An acrylic polyol is an acrylic oligomer having a plurality of hydroxyl groups in an acrylic chain, which is formed by polymerizing an acrylic monomer containing a hydroxyl group terminal with methyl acrylate or methyl meta-acrylate.
  • Various types of acrylic polyols formed by selecting specific acrylic monomers and adjusting their molecular weights are commercially available.
  • a polybutadiene polyol is a copolymer of butadiene containing a hydroxyl group at a terminal thereof and a compound having double bonds. It is a polyol with a relatively high level of hydrophobic property.
  • a metal catalyst or an amine catalyst may be used as a catalyst that promotes urethanizing reaction of the polyol component and the polyisocyanate.
  • a metal catalyst or an amine catalyst may be used as the metal catalyst.
  • the metal catalyst octylic zinc, octylic lead, dibutyltin dilaurate, dibutyltin acetate and the like can be listed up.
  • the amine catalyst triethylene diamine, NN-dimethyl piperazine, N-methyl morpholine and the like can be listed up. The catalyst normally added into the polyol component.
  • the multifunctional polyisocyanate component (a) and the multifunctional polyol component (b) are blended in quantities determined by calculating the NCO radix and the OH radix and setting the NCO/OH ratio of the NCO radix and the OH radix to a value close to 1.0.
  • NCO/OH ratio is set in a range from 0.7 to 1.0, preferably from 0.7 to 0.9, and more preferably 0.75 to 0.85, by making an average functional radix of the multifunctional polyisocyanate component (a) to 2.1 or greater (preferably 2.0 to 4.0) and making an average functional radix of the multifunctional polyol component (b) to 3.0 or greater (preferably 3.0 to 5.0).
  • an average functional radix of the multifunctional polyisocyanate component (a) to 2.1 or greater (preferably 2.0 to 4.0) and making an average functional radix of the multifunctional polyol component (b) to 3.0 or greater (preferably 3.0 to 5.0).
  • the two-pack reaction hardening type urethane resin solution (B) contains polyether chains as indicated in the chemical structure formula presented below.
  • the polyether chain is a soft component and has a chemical structure which is easy to be softened, decomposed and burned.
  • the polyether chains are contained in the two-pack reaction hardening type urethane resin solution (B) within a range from 5% to 35%. The range is set in a reason why: because the polyether chains are soft components, when they are contained over 35%, hardness of the hardening matter becomes smaller than Shore D hardness 65 and rubber elasticity appears strong, so that hardness to the polystyrene powder-sintered laminated resin model becomes unbalance.
  • plasticizer (c) used in the present invention is explained.
  • the plasticizer (c) used in the present invention is an inactive chemical compound having no functional group that induces a chemical reaction with volatility insignificant enough to be disregarded.
  • the plasticizer (c) may be an ester plasticizer, an ether plasticizer or an ester/ether plasticizer. More specifically, typical examples of the ester plasticizer are dioctyl adipate (DOA), dioctyl phthalate (DOP) and dibutyl phthalate (DBP).
  • DOA dioctyl adipate
  • DOP dioctyl phthalate
  • DBP dibutyl phthalate
  • ether plasticizer examples include ethylene glycol dibutyl ether, ethylene glycol diphenyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl butyl ether, diethylene glycol dibutyl ether, triethylene glycol diethyl ether, triethylene glycol diethyl ether, triethylene glycol diethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol diethyl ether and the like.
  • ethyl/ester plasticizer examples include ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol mono phenyl ether acetate and the like.
  • the plasticizer (c) is used in a quantity that amounts to 2 to 20 wt. % relative to the entire weight of the two-pack reaction hardening type urethane resin solution (B). If the content of the plasticizer (c) exceeds 20 wt. %, the plasticizer (c) bleeds over the surface of the resin model readily to cause stickiness. If, on the other hand, the plasticizer (c) is used in a quantity amounting to less than 2 wt. % the thermally decomposed and melted resin does not flow out readily during the dewaxing/baking processes since the plasticizer (c), which is a highly viscous liquid at room temperature but has a lower level of viscosity at higher temperatures, is not contained in sufficient quantity.
  • the present invention was conceived based upon the finding that a maximum content for the plasticizer (c) can be achieved by rapidly setting the resin within less than 5 minutes of working life and trapping the plasticizer (c) having undergone phase separation from the cured resin in the three-dimensional network structure of the cured resin in a state of micro dispersion.
  • plasticizer (c) contains polyether chains as indicated in the chemical structure formula presented below.
  • the polyether chain is a soft component and has a chemical structure which is easy to be softened, decomposed and burned.
  • the polyether chains are contained in the plasticizer (c) within a range from 0% to 80%.
  • the present invention was conceived based upon the finding that a maximum content for the plasticizer (c) can be achieved by rapidly setting the resin within less than 5 minutes of the work life and trapping the plasticizer (c) having undergone phase separation from the cured resin in the three-dimensional network structure of the cured resin in a state of micro dispersion.
  • phase separation micro dispersion can be regarded as a state in which the plasticizer (c) is enclosed by the cured resin assuming a honeycomb structure.
  • the cured resin assuming the honeycomb structure has superior physical strength, and the honeycomb structure can also be regarded as a three-dimensional structure within which the plasticizer (c) is secured within the honeycomb and is not allowed to be released to the outside.
  • the structure does not allow the plasticizer (c) to bleed over the surface of the hardened matter to induce tackiness even when the plasticizer is contained at a relatively high ratio.
  • phase separation micro dispersion structure If the phase separation micro dispersion structure is not adopted, the plasticizer is dissolved into the hardened resin, and once it reaches the saturation level, the plasticizer becomes bled over the surface of the hardened matter to result in tackiness. If the extent of bleeding is significant, the surface becomes sticky.
  • the phase separation micro dispersion structure can be observed through an electron microscope.
  • the formation of the phase separation micro dispersion structure needs to be aided by rapidly hardening the resin within a working life of 5 minutes or less.
  • the working life should be set to 3 minutes or less, and even more desirably to 1 to 2 minutes. If the work life is set to 5 minutes or more, the process of phase separation micro dispersion cannot be completed with ease, and since it will take a day or more to disengage the model during the model production, the model production will become an extremely slow process.
  • the plasticizer (c) When the plasticizer (c) is contained in the two-pack reaction hardening type urethane resin solution (B), it needs to be uniformly dissolved in the liquid resin, whereas the phase separation micro dispersion of the plasticizer from the cured resin is promoted during the reactive setting stage so that the micro dispersed plasticizer is trapped by the time the reactive setting process is completed, thereby preventing bleeding of the plasticizer onto the surface.
  • the composition of the two-pack reaction hardening type urethane resin solution must be designed so as to strike an optimal balance by taking into consideration the factors discussed above. Namely, the composition must be designed within the range over which the hydrophilic and hydrophobic properties of the plasticizer (c) and the reactive setting resin are perfectly balanced.
  • hydrophilic segment with an alkylene oxide chain and to form the hydrophobic segment with a hydrocarbon chain.
  • the properties of the hydrophilic segment and the hydrophobic segment are determined by selecting a specific type of raw monomer. A certain degree of dissociation should be assured with regard to the balance between the hydrophilic property and the hydrophobic property. If the two-pack reaction hardening type urethane resin solution (B) contains a large number of ethylene oxide chains, the hydrophilic property becomes more pronounced, whereas if the ethylene oxide chains are replaced with propylene oxide chains, the level of hydrophilic property is lowered.
  • the hydrophobic property of the two-pack reaction hardening type urethane resin solution (B) becomes more pronounced.
  • the hydrophilic property and the hydrophobic property of the two-pack reaction hardening type urethane resin solution (B) can be adjusted over a specific range.
  • the hydrophilic property and the hydrophobic property of the plasticizer (c) itself can be adjusted within a certain range.
  • the terminal of the plasticizer is constituted with alkyl ether
  • the level of the hydrophobic property increases as it changes to methyl ether, to ethyl ether, to butyl ether, and then to phenyl ether.
  • hydrophilic segments and the hydrophobic segments are connected so as to take three-dimensional network structure in a chemical reaction such as light/heat radical polymerization or cationic polymerization of double bond monomer, epoxy/amine addition condensation, polyol/polyisocyanate additional condensation or the like.
  • Content of the plasticizer (c) liquefied at normal temperature in the two-pack reaction hardening type urethane resin solution (B) set under thus balance is within a range from 10 to 30 wt. %.
  • the content exceeds 30 wt. %, it exceeds suitable quantity of the phase separation micro dispersion, so that the bleeding of the plasticizer (c) is happened over the surface of the hardened matter and the surface becomes tacky and sticky.
  • the content becomes lower than 10 wt. % heating, decomposition and flown-off of the resin model in the dewaxing/burning process becomes worse, it causes to cracks.
  • the alkylene oxide chain is a soft component and a segment easy to be softened, decomposed, melted or burned off at heating or at high temperature. Because the segments are distributed in the hardened resin, melting, decomposing, flown-off and burn-out is completed suitably.
  • the alkylene oxide chains are embedded in a hardening type resin body or the plasticizer, and contained in the two-pack reaction hardening type urethane resin solution (B) constituting of the reaction hardening type resin body and the plasticizer within a range from 5 to 30 wt. %, preferably 10 to 25 wt. %. When the content exceeds 30 wt. %, because the resin becomes very soft, the model is difficult to hold a shape of itself. When the content becomes lower than 5 wt. %, because the softening, decomposing and burning performance become worse at heating or at high temperature, burned-off performance as a burned-off model is damaged.
  • An embodiment of the two-pack reaction hardening type urethane resin solution (A) is as follows.
  • 17.0 wt. units of 2-ethyl hexyl adipate to be used as a plasticizer were placed in a four-neck flask, and the mixture was thoroughly blended and then dehydrated by agitating the mixture for one hour at 100° C. in a vacuum while allowing nitrogen gas to be absorbed therein through capillaries. Cooling down not more than 50° C., 0.01 wt. units of an anti-foam agent and 0.5 wt.
  • Test specimens for evaluating an adhesive property are prepared. Polystyrene powder-sintered laminated plates as the test specimen were polished by sandpaper to make the surfaces flat. The sintered and laminated plates were impregnated in the two-pack reaction hardening type urethane resin solution described in the above embodiment, and was picked up from it after decreasing pressure, and the test specimen was formed by being dried and hardened during 30 minutes and the test specimen was formed by being dried and hardened during one day. A flat surface of each test specimen is cut crosswise at intervals of 1 mm to form one hundred squares. An adhesive tape was put on the surface with one hundred squares and then it was taken off from the surface vigorously, and then exfoliation of two-pack reaction hardening type resin solution hardening layers was judged visually.
  • Test specimens were prepared. A polystyrene powder-sintered laminated plate is made to a non-treatment specimen, and a polystyrene powder-sintered laminated plate performed with smoothing treatment according to the present invention is made to a specimen for evaluation. Smoothness of each surface of the specimens was judged by light finger touch to them to be evaluated by feeling.
  • the two-pack reaction hardening type urethane resin solution is a reaction hardening type, good adhesive property to the solid surface is achieved. Besides, because porous rough surface is coated in a partly impregnating condition to appear an anchor effect, so that the adhesive property becomes better.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
  • Polyurethanes Or Polyureas (AREA)
US10/586,638 2004-01-23 2004-01-23 Method of Smoothing Surface and Process of Lost Wax Precious Casting with Resin Model Having Its Surface Smoothing by the Method Abandoned US20070204967A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2004/000596 WO2005070587A1 (ja) 2004-01-23 2004-01-23 表面平滑化法及び該方法によって平滑化した表面を有する樹脂模型を用いたロストワックス精密鋳造法

Publications (1)

Publication Number Publication Date
US20070204967A1 true US20070204967A1 (en) 2007-09-06

Family

ID=34805291

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/586,638 Abandoned US20070204967A1 (en) 2004-01-23 2004-01-23 Method of Smoothing Surface and Process of Lost Wax Precious Casting with Resin Model Having Its Surface Smoothing by the Method

Country Status (3)

Country Link
US (1) US20070204967A1 (ja)
EP (1) EP1707288A1 (ja)
WO (1) WO2005070587A1 (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115284609A (zh) * 2022-08-01 2022-11-04 深圳市金石三维打印科技有限公司 光固化3d打印机的构件表面平滑打印方法、装置及设备

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20010043990A1 (en) * 2000-03-21 2001-11-22 Chong Kong Fok Plastic components with improved surface appearance and method of making the same

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5934460B2 (ja) * 1977-04-08 1984-08-22 三菱重工業株式会社 マイクロ波加熱用樹脂模型
JP3858222B2 (ja) * 2002-10-01 2006-12-13 湘南デザイン株式会社 表面平滑化法及び該方法によって平滑化した表面を有する樹脂模型を用いたロストワックス精密鋳造法

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20010043990A1 (en) * 2000-03-21 2001-11-22 Chong Kong Fok Plastic components with improved surface appearance and method of making the same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115284609A (zh) * 2022-08-01 2022-11-04 深圳市金石三维打印科技有限公司 光固化3d打印机的构件表面平滑打印方法、装置及设备

Also Published As

Publication number Publication date
EP1707288A1 (en) 2006-10-04
WO2005070587A1 (ja) 2005-08-04

Similar Documents

Publication Publication Date Title
DK1664223T3 (en) Two-component composition for the production of flexible polyurethane gel coats
CA2007899C (en) Method for preparing and applying a sprayable, light stable polyurethane
US4847026A (en) Method of molding an artifcial urethane rock
CN114728400A (zh) 抛光垫的增材制造的组合物和方法
WO2020131675A1 (en) Energy absorbing dual cure polyurethane elastomers for additive manufacturing
US20060144555A1 (en) Method for producing molds for lost wax precision casting
US20070204967A1 (en) Method of Smoothing Surface and Process of Lost Wax Precious Casting with Resin Model Having Its Surface Smoothing by the Method
US5739245A (en) Plastics with a content of silane, ether, urethane and urea groups and their use as dental composition
TWI641640B (zh) 於物體上製造聚合物材料層之三維沈積方法
CN109320666A (zh) 一种uv-pu双固化3d打印树脂及其制备方法和用途
JP2021516180A (ja) 潜在性硬化樹脂および関連する方法
JPH0665692B2 (ja) 触媒組成物
JP3858222B2 (ja) 表面平滑化法及び該方法によって平滑化した表面を有する樹脂模型を用いたロストワックス精密鋳造法
WO2004069447A1 (ja) 樹脂模型の一体成形方法
JPH05155976A (ja) 高温での伸び物性に優れたポリウレタン樹脂
CN114752311B (zh) 一种tpu保护膜及其制备方法
US20070158870A1 (en) Process for producing resin model and process of lost wax precision casting with the resin model
JP3637444B2 (ja) 精密鋳造法及び該精密鋳造法によって製造された精密鋳造品。
JP3684532B2 (ja) 樹脂模型の製造方法及び該樹脂模型を用いたロストワックス精密鋳造法
JP3605766B2 (ja) 焼失樹脂模型及びこの焼失樹脂模型を用いた精密鋳造法
CN115819711B (zh) 反应挤出3d打印硅橡胶-聚脲材料及其应用
CN116120878B (zh) 一种耐喷砂、易打磨聚氨酯嵌缝胶及其制备方法
US20070145633A1 (en) Method for manufacturing hollow model
JPH0939167A (ja) Ｆｒｐ成形品およびその製造方法
US20070131378A1 (en) Burn-off resin model and precision casting method adopted in conjunction with burn-off resin model

Legal Events

Date Code Title Description
AS Assignment

Owner name: SHONAN DESIGN CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KITA, TARO;KAMATA, KAZUKI;MATSUMURA, MINORU;AND OTHERS;REEL/FRAME:018130/0731

Effective date: 20060704

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION