JP2001254060A - Thermosensible adhesive paper three-dimensional shaping machine and three dimensional shaped item - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosensible adhesive paper for a three-dimensional shaping machine of which the paper has a preferable thermosensibility to use for a three-dimensional shaping machine of a thermal adhesion type and can give a high dimensional accuracy by effectively suppressing the extension and shrinkage of a shaped item caused by its absorbing and releas ing water from air. SOLUTION: The thermosensible adhesive paper is used in a three-dimensional shaping machine to prepare a three-dimensional shaping item, in which machine a thrmosensible adhesive paper (31) having a thermosensible adhesive layer on its lower side is provided continuously onto the upper surface of a stage (32) which is movable upward and downward, the thermosensible adhesive paper is adhered to a surface of the stage or another sheet of thermosensible adhesive paper already provided by heating and pressurizing the surface, a laminated item (44) having two or more layer is formed by drawing cutting lines (41, 42, and 43) on the thermosensible adhesive paper and unnecessary portions are cut off from the laminated item. For the thermosensible adhesive paper, 5-30 g/m2 of a thermosensible adhesive layer whose melting point is 50-150 deg.C is laminated on the side of a base paper of 40-200 g/m2 of a weight per unit area. The base paper has a cellulose fiber as its main component and contains 5-60 wt% of a thermal adhesive binder material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive adhesive paper used for a heat bonding type three-dimensional printing machine, and a three-dimensional printed article obtained by using the same.

[0002]

2. Description of the Related Art Conventionally, when designing various parts for automobiles, parts for home electric appliances, various toys, etc., a three-dimensional model (three-dimensional molded article) is manufactured using clay, wood, metal, or the like. That was being done. In addition, a three-dimensional molded article was manufactured using wood or the like, and a casting was manufactured by a method in which a mold was manufactured using sand or the like based on the three-dimensional molded article, and a molten metal was poured into the mold and cooled and solidified. .

Recently, with the development of computer technology, various methods for automatically producing these three-dimensional objects have been proposed. For example, a method of producing a three-dimensional structure using an ultraviolet curable resin has been proposed. In this method, the bat is filled with a liquid ultraviolet-curing resin, the stage placed at the bottom is raised, the resin on the stage is irradiated with ultraviolet rays to cure the resin, the stage is lowered, and then raised again to emit the ultraviolet rays. This is a method of obtaining a three-dimensional structure by repeating irradiation. A method of obtaining a three-dimensional structure by laminating the resin while melting the resin has also been proposed.

Japanese Patent Application Laid-Open No. 9-66565 discloses that a heat-sensitive adhesive sheet having a heat-sensitive adhesive layer provided on the back surface is sequentially supplied to the upper surface of a vertically movable table, as will be described in detail later. The paper is heated while being pressed while being adhered to the table or the surface of the already supplied heat-sensitive adhesive sheet, and a cut line of a predetermined shape is provided on these heat-sensitive adhesive sheets to form a laminate composed of a plurality of layers. However, there has been proposed a method of manufacturing a three-dimensional structure by removing unnecessary portions from the laminate.

[0005] The disadvantages common to the above-described method of obtaining a three-dimensional object using the resin are that the accuracy of the object is poor,
The problem is that processing when the object becomes unnecessary becomes a problem. The method using the heat-sensitive adhesive sheet of JP-A-9-66565 has higher accuracy than the method using a resin,
When heat-sensitive adhesive paper is used as the heat-sensitive adhesive sheet, there is an advantage that the incineration treatment is easier compared to a molded article using resin, but the heat-bonding efficiency of the heat-sensitive adhesive paper is poor, so that the molding takes a long time. Was a drawback. JP-A-9-66565 does not disclose any means for solving this drawback.

As a result of intensive studies, the present inventors have succeeded in developing a heat-sensitive adhesive paper which has solved these problems.
A patent application has already been filed as Japanese Patent Application No. 11-183255. The heat-sensitive adhesive paper for a three-dimensional molding machine according to the invention of the prior application is such that a heat-sensitive adhesive paper having a heat-sensitive adhesive layer provided on the back surface is sequentially supplied to the upper surface of a vertically movable table, and the surface of the supplied heat-sensitive adhesive paper is While pressing while heating, it adheres to the surface of the base or the already supplied heat-sensitive adhesive paper, and a cut line of a predetermined shape is provided on these heat-sensitive adhesive paper to form a laminate composed of a plurality of layers. In a heat-sensitive adhesive paper used for a three-dimensional printing machine that obtains a three-dimensional printing object by removing an unnecessary portion from a laminate, a heat-sensitive adhesive layer having a melting temperature of 50 to 150 ° C. has a basis weight of 40 to 200 g / m ^2. 5 to 30 g / m ² on the back surface of the base paper.

[0007]

Incidentally, there is a field in which high dimensional accuracy is required in the above-mentioned casting mold for manufacturing a casting, and in such a field, a general indoor environment (20 ° C., 40 to 60%) is generally used. RH) is required to suppress the expansion and contraction to 0.3% or less. However, a problem that is always encountered in the case of a wooden mold is that the wooden mold itself expands and contracts by absorbing and releasing moisture in the air. In addition, the three-dimensional structure formed by the present inventors using the heat-sensitive adhesive paper of the invention of the prior application does not necessarily satisfy the high dimensional accuracy as described above. Therefore, the above-mentioned prior application proposes that the surface of the three-dimensional structure is coated with a resin having low water vapor permeability such as vinylidene chloride to suppress the absorption and release of moisture and increase the dimensional accuracy.

However, when coating is performed after forming a three-dimensional model, a coating step is additionally required,
It is desired to impart high dimensional accuracy to the heat-sensitive adhesive paper itself, because it also increases the manufacturing cost.

Accordingly, the present invention provides a heat-sensitive adhesive which can be suitably used for a three-dimensional molding machine, and can effectively suppress expansion and contraction of a molded article by absorbing and releasing moisture in the air. An object of the present invention is to provide a heat-sensitive adhesive paper for a three-dimensional molding machine that can provide high dimensional accuracy without applying a coating to an object.

[0010]

According to the present invention, a heat-sensitive adhesive paper provided with a heat-sensitive adhesive layer on a back surface is sequentially supplied to an upper surface of a vertically movable table, and the surface of the supplied heat-sensitive adhesive paper is pressed. While heating to adhere to the table or the surface of the already supplied heat-sensitive adhesive paper, a cut line of a predetermined shape is provided on the heat-sensitive adhesive paper to form a laminate composed of a plurality of layers. In a heat-sensitive adhesive paper used for a three-dimensional printing machine that obtains a three-dimensional printing object by removing an unnecessary part from a paper, a heat-sensitive adhesive layer having a melting temperature of 50 to 150 ° C. is coated with a base paper having a basis weight of 40 to 200 g / m ² . 5-30 g / m ² on the back of
The heat-sensitive adhesive paper for a three-dimensional printing machine is characterized in that the base paper is mainly provided with cellulose fibers and contains a heat-adhesive binder substance in an amount of 5 to 60% by weight. In the present invention, the melting temperature is
It means a value measured according to “Method for measuring melting point of chemical products” specified in JIS K0064.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for using a heat-sensitive adhesive paper for three-dimensional printing according to the present invention will be described with reference to an example of a three-dimensional printing machine. FIG. 1 is a configuration diagram showing a state in which a three-dimensional molding machine described in FIG. 7 of the above-mentioned Japanese Patent Application Laid-Open No. 9-66565 is producing a molded object. In FIG. 1, reference numeral 32 denotes a vertically movable table, on which a material (heat-sensitive adhesive paper) 31 is sequentially fed from a supply roll 33 via a guide roll 34. 35 is front and back on the base 32 (left and right in the figure)
The material 31 is fed to the base 32 or heated by pressing the material 31 onto the base 32 while pressing the material 31 toward the base 32, thereby bonding the material 31 to the base 32 or the material already fed to the base 32. The new material 31 sent thereon is bonded to 31. 36 is provided on the upper side of the base 32,
2 is a movable optical head that can move back and forth and right and left, and sends a laser beam sent from a laser light source 38 via a mirror 37 onto the base 32 to cut the material 31 on the base 32. Has become.

Reference numeral 39 denotes a guide roll 34 sandwiching the base 32.
Guide rolls provided to face the
Is a take-up roll that takes up the unnecessary portion of the material 31 after use through the guide roll 39. When forming a molded article, first, the material 31 fed from the supply roll 33 is used.
Is wound around a take-up roll 40, and the heating roller 35 is moved on the base 32 to adhere the material 31 to the base 32. Next, a laser beam is generated while operating the laser light source 38 and moving the movable optical head 36, thereby cutting the contour 41 having a predetermined shape on the material 31 and cutting line 42 on the outer peripheral edge of the portion used for modeling. Are cut in the unnecessary portions, respectively.

Then, the base portion 3 is formed by the thickness of the formed layer.
2 is lowered, the take-up roll 40 is rotated, a new material 31 is placed on the cut material 31, and the above-described operation is repeated to form a multi-layer laminate 44. Obtaining an object by removing unnecessary portions from the laminate 44 is performed.

In Japanese Patent Application Laid-Open No. 9-66565, the use of a cutter instead of cutting with a laser beam prevents a portion constituting a modeled object from sticking to an unnecessary portion to prevent the removal of the unnecessary portion from becoming difficult. At the same time, a proposal has been made to make the device cheaper. The heat-sensitive adhesive paper for a three-dimensional printing machine of the present invention can provide a heat-sensitive adhesive paper that can be used for both laser cutting and cutter cutting.

Next, the base paper used for the heat-sensitive adhesive paper of the present invention will be described. The base paper used in the present invention is basically the same as the above-mentioned prior invention by the present inventors (Japanese Patent Application No. 11-18).
No. 3255) in which a predetermined amount of a heat-adhesive binder substance is contained in a base paper used for the heat-sensitive adhesive paper.

When a heat-sensitive adhesive paper is manufactured using a base paper containing a heat-adhesive binder material and the heat-sensitive adhesive paper is formed using a three-dimensional printing machine, the heat of a heating roller causes the heat-sensitive adhesive paper to produce the heat-sensitive adhesive paper. The heat-adhesive binder material is melted or softened and becomes tacky and adheres to cellulose fibers such as wood pulp and non-wood pulp, which are the main materials constituting the base paper,
As a result of the binder effect of binding the fibers,
It is difficult for the molded article, which is a laminate of the heat-sensitive adhesive paper, to absorb and release moisture in the air, so that an effect of suppressing expansion and contraction can be obtained.

The heat-adhesive binder used in the present invention preferably has a melting temperature of 50 to 180 ° C. When the temperature is lower than 50 ° C., blocking tends to occur when the base paper is stored in an overlapping state,
This is because, when the temperature exceeds the above range, the heat-adhesive binder substance is unlikely to be melted or softened even when heated by a heating roller during molding. In addition, as described later, when the melting temperature of the heat-sensitive adhesive applied to the base paper back surface exceeds 150 ° C., the adhesive becomes difficult to melt even when heated by a heating roller, so that the adhesiveness between the heat-sensitive adhesive papers is poor. However, as the heat-adhesive binder substance contained in the base paper, a substance having a higher melting temperature of about 180 ° C. can be used. This is because the heat of the heating roller is transmitted through the base paper to the heat-sensitive adhesive layer on the back surface of the base paper, but since the base paper itself is in direct contact with the heating roller, it has a melting temperature higher than the melting temperature of the heat-sensitive adhesive. This is because even a heat-adhesive binder substance can be melted or softened.

The proportion of the heat-adhesive binder substance contained in the base paper is in the range of 5 to 60% by weight based on the total weight of the base paper. If the content is less than 5% by weight, the binder effect of the thermoadhesive binder substance on the cellulose fibers cannot be sufficiently obtained, and the desired effect of suppressing the absorption and release of water cannot be obtained.
On the other hand, when the content exceeds 60% by weight, a part of the heat-adhesive binder substance softens and adheres to the surface of the cylinder dryer during the papermaking of the base paper, so that the dryer is easily stained. Even in the case of impregnating the heat-adhesive binder substance, the heat-adhesive binder substance adheres to the paper roll, and the roll is easily stained.

As a method for incorporating the heat-adhesive binder substance into the base paper, for example, the following method can be adopted. 1) A method of adding a heat-adhesive fiber to a stock as a heat-adhesive binder material to form a base paper; 2) Adding a heat-adhesive particle to a stock as a heat-adhesive binder material to form a base paper. 3) A method of impregnating the base paper with a heat-adhesive binder substance during or after the papermaking of the base paper, 4) A method by a combination of the above methods.

A method for producing a base paper containing a heat-adhesive binder substance by using the above method will be described more specifically. 1) A method of adding heat-adhesive fiber to paper to form a paper stock Hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood bleached sulphite pulp (LBSP), softwood bleached sulphite pulp (NBS)
Wood pulp such as chemical pulp such as P), mechanical pulp such as groundwood pulp (GP) and thermomechanical pulp (TMP), cotton pulp, hemp, bagasse, kenaf,
Non-wood pulp such as esparto, mulberry, mitsumata, ganpi etc. alone or in combination with two or more types of cellulose fiber,
A predetermined amount of heat-adhesive fiber is added, and a dry paper strength agent such as starch and polyacrylamide, a wet paper strength agent such as polyamide / polyamine / epichlorohydrin resin, urea formalin resin, melamine formalin resin, rosin-based, alkyl Ketene dimer type, alkenyl succinic anhydride type, styrene-acrylic type, stearic anhydride type, petroleum resin type, etc., sulphate band, aluminum chloride, sodium aluminate, basic aluminum chloride, basic polyaluminum hydroxide, etc. A paper material appropriately mixed with a fixing agent, a retention improver, a drainage improver, an antifoaming agent, a dye, a color pigment and the like is usually used in a freeness of 250 to 550.
mlC. S. F. And a paper machine using a known paper machine such as a fourdrinier paper machine or a circular net paper machine.
At this time, it is also possible to apply an auxiliary agent such as starch, polyvinyl alcohol, or various surface sizes to the paper surface during the paper making by a size press device or the like. Further, if necessary, a machine calendering treatment or a super calendering treatment is performed to appropriately improve the surface smoothness.

In the present invention, it is preferable to use a wet paper strength enhancer in combination with the papermaking of the base paper. By using the wet paper strength enhancer, it is possible to further reduce the phenomenon that the molded article after molding absorbs moisture in the air and expands, and is deformed over time.

A typical example of the heat-adhesive fiber is a polyolefin-based synthetic pulp. Polyolefin synthetic pulp includes, for example, those manufactured by a well-known method called a flash method using polyethylene or polypropylene as a raw material, and is available as a commercial product (for example, trade name “SWP”, manufactured by Mitsui Chemicals, Inc.).

As the heat-adhesive fiber, it is also possible to use a single fiber formed of a thermoplastic resin such as polyethylene, polyethylene terephthalate, ethylene-vinyl acetate copolymer, nylon, vinyl chloride-vinyl acetate copolymer and the like. it can.

A non-adhesive portion made of a material that is relatively hard to melt or does not melt along the axial direction of the fiber, while having an adhesive portion made of a heat-adhesive resin that is relatively easy to melt on the surface of the fiber. So-called composite fibers with
It can be used as a heat-adhesive fiber. Such composite fibers are
The adhesive portion adheres to the surrounding cellulose fibers by heating, and a fibrous non-adhesive portion that is not easily melted or deformed even by heating remains, which is preferable because a good three-dimensional network structure can be maintained.

As such a composite fiber, for example, a sheath portion formed of a material that can be melted by heat treatment,
A conjugate fiber having a core-sheath structure including a core portion formed of a material that is harder to melt or is not melted compared to the sheath portion by the same heat treatment can be exemplified. More specifically,
Using two kinds of thermoplastic resins whose melting temperature or softening temperature are different from each other, the core portion is formed by a resin having a relatively high melting temperature or softening temperature, and a sheath portion is formed by a resin having a relatively low melting temperature or softening temperature. Can be used. Examples of combinations of resins constituting the core-sheath structure include polypropylene / polyethylene, polypropylene / ethylene-vinyl acetate copolymer, polyethylene terephthalate / polyethylene, polyethylene terephthalate / polyethylene terephthalate, polyethylene terephthalate / polypropylene, and polyethylene terephthalate / ethylene-vinyl acetate. There are copolymers, nylon / nylon, and the like (the left side of the hatched portion represents the core portion, and the right side represents the sheath portion). As a composite fiber having a core-sheath structure, 1
Not only one having a core portion formed thereon but also one having a plurality of core portions arranged in parallel in a sheath portion can be used.

A first portion formed of a material that can be melted by the heat treatment, and a second portion formed of a material that is harder to melt or less meltable than the first portion by the same heat treatment. Can be exemplified as a composite fiber having a side-by-side structure in which the fibers are arranged in parallel along the axial direction of the fiber and integrated. More specifically, a composite fiber having a side-by-side structure in which the first portion and the second portion are formed using two types of thermoplastic resins having different melting temperatures or different softening temperatures can be used.

2) Method of paper-making by adding heat-adhesive particles to paper stock Polyethylene resin, polyvinyl chloride resin, polyester resin, polyvinyl acetate resin, ethylene-vinyl acetate copolymer resin, polyacrylate resin, etc. A material that has been pulverized into particles or a material obtained by converting the particles into an emulsion or dispersion is added to the same stock as described in the above method 1), and the obtained stock is used. Make a base paper.

3) A method of impregnating the base paper with a heat-adhesive binder substance during or after the formation of the base paper When the base paper is formed using the same stock as described in the method 1) above, The base paper is impregnated with the heat-adhesive binder substance using a device such as a size press installed in the middle, or the heat-adhesive binder substance is converted into the base paper using the impregnation apparatus after the base paper is formed. Impregnate.

Examples of the heat-adhesive binder material to be impregnated include polyvinyl chloride resin, polyvinyl acetate resin,
Vinyl chloride-vinyl acetate copolymer resin, polyethylene resin, ethylene-vinyl acetate copolymer resin, acrylate copolymer resin, polyamide resin, chlorinated polypropylene resin, unsaturated polyester resin, polyurethane resin,
A resin solution in which a thermoplastic resin such as a modified polyvinyl alcohol resin or the like is dissolved in water or an organic solvent, an aqueous emulsion, or a dispersion can be used.

4) A method based on a combination of the above methods, and a method appropriately combining the above methods 1) to 3) can also be adopted. As an example thereof, a method of adding a heat-adhesive fiber and heat-adhesive particles to a stock to form a base paper and further impregnating with a heat-adhesive binder substance can be mentioned.

In the present invention, the basis weight of the base paper is from 40 to
200 g / m ² , more preferably 60 to 120 g / m ²
And When the grammage is less than 40 g / m ² , it takes a long time to form a predetermined thickness, and the efficiency becomes poor.
If it exceeds 0 g / m ² , the heat bonding efficiency will be poor and the bonding strength between the heat-sensitive adhesive papers will be insufficient. When the basis weight of the base paper is 60
When it is set to 120 g / m ² , the balance between the production efficiency and the heat bonding efficiency is improved.

In the present invention, a moisture-proof layer can be further provided on the base paper. By adopting such a configuration, it is possible to further reduce the possibility that the molded article after molding absorbs moisture in the air and expands, and is deformed over time. The moisture-proof layer is formed by applying a resin having a large moisture-proof effect, such as a vinylidene chloride resin, to one or both sides of a ² to 15 g / m ² base paper.

The heat-sensitive adhesive used in the present invention is, for example,
Acrylate copolymer, methacrylate copolymer, polyvinyl acetate, vinyl acetate-acryl copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-acryl copolymer, vinyl chloride-ethylene copolymer Polymer, unsaturated polyester resin, ionomer resin, S
Mainly thermoplastic resin such as BR, MBR, NBR,
Additives such as various plasticizers and waxes are added to this as needed, and those having a melting temperature of 50 to 150 ° C. in a state where various additives are added to a thermoplastic resin can be used. If the temperature is lower than 50 ° C., blocking occurs during storage of the paper, and if it is higher than 150 ° C., adhesion by heat becomes extremely poor.

The form of the heat-sensitive adhesive may be any of a water-based, solvent-based, and hot-melt-based adhesive. However, when a solvent-based heat-sensitive adhesive is used, a process for preventing the penetration of the solvent into the base paper is required. In the present invention, it is preferable to use a water-based heat-sensitive adhesive since it must be applied.

As the plasticizer added to the thermoplastic resin used for the heat-sensitive adhesive, known plasticizers such as dicyclohexyl phthalate and dihexyl phthalate can be used. Thereby, the thermoplastic resin easily sticks when the heat-sensitive adhesive paper is heated and laminated, and the required adhesive strength can be obtained at a lower temperature than when no plasticizer is added. In the present invention, waxes such as natural wax and synthetic wax can be added to the thermoplastic resin. This allows
This is because blocking can be prevented even when a resin having a low glass transition temperature is used. As other additives, various fillers, coloring agents such as dyes and pigments, antioxidants, thickeners and the like can be used.

In forming a three-dimensional structure using the heat-sensitive adhesive paper of the present invention, it is sometimes preferable that the heat-sensitive adhesive paper has good hot tack properties. Hot tack is
For example, when confectionery is filled in a bag of a light packaging material (usually a polymer film provided with a heat-sensitive adhesive layer) for high-speed automatic packaging, this is one of the characteristics that are very important. The bonded portion of the bag of the packaging material put on the high-speed automatic packaging machine is sandwiched between metals, heated quickly, and thermally bonded under pressure. The thermal bond is released from the pressurized state when the adhesive layer is still molten. When the portion hitting the bottom of the bag is in such a state, the contents (confectionery) are filled at a high speed, so that the adhesive portion still in the molten state is subjected to the action of being peeled off due to the load of the contents. The hot tack property of the heat-bonded part means that the adhesive keeps its perfect state in the molten state before the adhesive cools and solidifies, and the good hot tack property means that the filling process and the bonding process can be performed at a higher speed. Means that you can do it with

In the present invention, when the hot tack property is evaluated, it is evaluated using a numerical value called "hot tack value". This hot tack value means a value measured by a heat seal tester (trade name “heat seal tester TP701A”, manufactured by Tester Sangyo Co., Ltd.). FIG. 2 shows the principle of the measurement. 3 is an upper seal bar (25 mm in width x 300 mm in length), and 4 is a lower seal bar. Sample 2, that is, two sheets of heat-sensitive adhesive paper are prepared in the form of a long sheet, and are sandwiched between the upper seal bar 3 and the lower seal bar 4 such that the front surface and the back surface (heat-sensitive adhesive-coated surface) overlap. Is installed as follows. In two samples 2,
Through the guide rolls 1 each having a diameter of Rmm, the angle θ
A load of Wg is applied with a certain degree. At this time, the extended portion of the sample is pulled by a load of 2 × Wg so that the sample does not move. The upper seal bar 3 descends to transfer the sample between the lower seal bar 4 and the seal width 25 mm.
The seal length is 300 mm and the weight is Qkg. The upper seal bar 3 can be heated, and the seal temperature can be set to T ° C. After the sealing, the upper seal bar 3 is lifted, and at the same time, the load of 2 × Wg applied to the feeding portion of the sample is released, and the seal 2 is sealed by the load Wg applied to the tip of the sample.
The samples are instantaneously peeled off. The distance in the long direction peeled off at that time is measured and defined as a hot tack value (mm).
That is, the lower the hot tack value, the better the hot tack property.

When molding a three-dimensional molded article using the heat-sensitive adhesive paper of the present invention, for example, when a situation in which the molded article is to be produced urgently is attempted to increase the speed of the three-dimensional molding machine, If an attempt is made to increase the reciprocating speed of the heating roller, the heat-sensitive adhesive may be insufficiently melted to cause poor bonding. In order to solve this, the temperature of the heating roller may be increased. However, in this case, the heat-sensitive adhesive is in an over-molten state, so the amount of heat trapped inside the modeled object is larger than the amount of heat received from the heating roller radiated to the outside air, and the solidification of the heat-sensitive adhesive is delayed, causing internal distortion. This may cause a problem that the molded article is deformed (the adhesive migrates and swells in the thickness direction of the laminate). As a result of various studies aimed at solving this problem, the present inventors have found that this deformation is unlikely to occur when the hot tack value of the heat-sensitive adhesive is below a certain value.

As a result of investigations by the present inventors, the diameter of the guide roll in the heat seal tester shown in FIG.
0 mm, the pressure load of the upper seal bar is 1 kg / cm ² ,
The hot tack value when the compression time is 1 second, the weight W applied to the tip of the sample is 30 g, the angle θ is 20 degrees, and the sealing temperature is [the melting temperature of the adhesive + 30] ° C, is the deformation due to the internal distortion of the modeled object. When the value is 30 mm or less, there is no problem that the molded article is deformed due to internal strain even if the adhesive is in an over-melted state.
In addition, if a heat-sensitive adhesive paper having a hot tack value of 30 mm or less is used, there is also an advantage that a driver of a three-dimensional molding machine does not require skill in process control such as molding speed and temperature of a heating roller.

Hot tack refers to the fact that the heat-sensitive adhesive keeps its seal intact from the molten state until it cools and solidifies, and is generally highly correlated with the cohesive strength and viscosity of the adhesive. There is no unique method to reduce the hot tack value to 30 mm or less. Generally, it is sufficient to increase the cohesive strength and viscosity, and the molecular weight of the heat-sensitive adhesive, the addition of a tackifier, and the elasticity during melting. The rate may be considered. However, it goes without saying that it is important to design in consideration of other physical properties and factors, such as the melting temperature of the heat-sensitive adhesive and the amount of coating.

According to the results of various studies conducted by the present inventors, the heat-sensitive adhesive is an ethylene-vinyl acetate copolymer resin having a melting temperature of 60 to 90 ° C. The agent is a mixture of an ethylene-vinyl acetate copolymer resin and a wax, and the one having a melting temperature of 60 to 90 ° C. is particularly suitable for the present invention because of its good heat bonding efficiency and excellent blocking resistance. It turned out that it could be used.

When the coating liquid is water-based, the heat-sensitive adhesive is
Normally, using a coating machine such as an air knife coater, blade coater or roll coater, a gravure coater or a roll coater for solvent type, or a hot melt coater or extrusion coater for hot melt type. Apply to Coating amount is 5 to 30 g / m
² (in terms of dry weight), preferably 10 to 25 g / m ² . If the coating amount is less than 5 g / m ² , the adhesiveness will be poor, and if it exceeds 30 g / m ² , blocking will easily occur, and the adhesiveness will be saturated and it will be economically disadvantageous to apply further. Because it becomes.

In the present invention, when applying the heat-sensitive adhesive to the base paper, it is particularly preferable to form fine irregularities on the surface of the heat-sensitive adhesive layer. By doing so, the surface of the adhesive becomes "point contact" at the convex portion during storage of the heat-sensitive adhesive paper, and blocking resistance can be improved.

Any means may be used to form the fine irregularities on the surface of the heat-sensitive adhesive layer. However, adding powder to the heat-sensitive adhesive and reducing the coating amount of the heat-sensitive adhesive layer It is a simple method to form the film by changing the thickness, and the method can be suitably adopted in the present invention.

As the powder to be added to the heat-sensitive adhesive, it is preferable to use, for example, cellulose powder, starch particles, glass beads, polyethylene particles, silica particles, etc., which have a large effect of preventing blocking and a low rate of lowering the adhesive force. Can be used for Usually, the particle diameter of these powders is 3 to 200 μm.
m.

As a means for forming a fine uneven shape by partially changing the coating amount of the heat-sensitive adhesive layer, the adhesive is applied by a gravure coating machine and a concave portion having a predetermined shape is provided. A method of forming irregularities of a predetermined shape by filling the concave portion of the gravure roll with an adhesive and transferring it to the base paper, or applying a coating liquid with a high coating solution viscosity and applying a roll coater to form a streaky coated surface of the irregularities And a method of forming wire streaks by rubbing the coated surface immediately after coating with a wire bar.

When a three-dimensional molded article is manufactured using a heat-sensitive adhesive paper having a heat-sensitive adhesive layer having a fine uneven surface on the surface, the adhesive at the convex portion is formed by the roll pressure. Since it moves to the concave side, almost uniform adhesive force is exhibited as a whole. In addition, by adopting such a structure, the heat of the heating roller reaches the base paper during thermal bonding, the moisture contained in the base paper evaporates, there is no escape area, and the base paper is partially bonded due to floating. There is also an advantage that troubles that cause defects can be reduced.

A coating layer of a heat-sensitive adhesive is provided on the back surface of the base paper by the method described above, and a small amount of a thermoplastic resin is coated on the surface of the base paper (the surface opposite to the coating layer of the heat-sensitive adhesive). Can also be appropriately performed. As the type of the thermoplastic resin, the same resins as those used for the heat-sensitive adhesive layer, that is, acrylate copolymer, methacrylate copolymer, polyvinyl acetate, vinyl acetate-acryl copolymer , An ethylene-vinyl acetate copolymer, an ethylene-vinyl acetate-acrylic copolymer, a vinyl chloride-ethylene copolymer, an ionomer resin, SBR, MBR, NBR and the like can be used. 5-5 g / m ²
And By providing this layer, familiarity with the heat-sensitive adhesive layer provided on the back surface of the base paper is improved, and strong adhesion is easily obtained. However, such a structure tends to cause a problem that the thermoplastic resin is transferred to the surface of the heat roller and contaminates the roller when producing a three-dimensional molded article. To prevent this problem, it is effective to coat the surface of the heat roller with a resin having excellent releasability, such as polytetrafluoroethylene resin.

[0049]

EXAMPLES The present invention will be described in detail below with reference to Examples and Comparative Examples, and all weights are dry weights.

[Preparation of base paper (A)] (without heat-adhesive binder substance) A raw pulp consisting of 25 parts by weight of NBKP and 75 parts by weight of LBKP was mixed with 400 ml of pulp. S. F. And beaten kaolin with pulp at 5% by weight and rosin size with pulp at 0.
6% by weight, 2% by weight of sulphate band relative to pulp, polyamine / polyamide / epichlorohydrin resin (trade name "WS-500", Nippon PMC Co., Ltd.) as wet paper strength agent
Pulp is added to prepare pulp by adding
Using a fourdrinier paper machine, base papers of various basis weights were formed according to a conventional method.

[Preparation of base paper (B)] 25 parts by weight of NBKP and 70 parts by weight of LBKP, polyethylene synthetic pulp (trade name "SWP E400", manufactured by Mitsui Chemicals, Inc.)
A raw pulp consisting of 5 parts by weight was mixed with 400 ml C.I. S. F.
5% by weight of kaolin with respect to pulp, 0.6% by weight of rosin sizing agent with respect to pulp, 2% by weight of sulphate band with respect to pulp, and polyamine polyamide polyamide as wet paper strength enhancer
Epichlorohydrin resin (trade name "WS-500")
Was added to 0.5% by weight of pulp to prepare a stock, and a base paper having various basis weights was formed using a Fourdrinier machine according to a conventional method.

[Preparation of Base Paper (C)] A raw pulp comprising 25 parts by weight of NBKP, 65 parts by weight of LBKP, and 10 parts by weight of a polyethylene-based synthetic pulp (trade name "SWP E400") was mixed with 400 ml C.P. S. F. And beaten kaolin with pulp at 5% by weight and rosin size with pulp at 0.6
A paper stock was prepared by adding 2% by weight of a sulfuric acid band to 2% by weight of pulp, and 0.5% by weight of pulp to a polyamine / polyamide / epichlorohydrin resin (trade name “WS-500”) as a wet strength agent. Using a fourdrinier paper machine, base papers of various basis weights were formed according to a conventional method.

[Preparation of Base Paper (D)] A raw pulp composed of 25 parts by weight of NBKP, 55 parts by weight of LBKP, and 20 parts by weight of a polyethylene synthetic pulp (trade name “SWP E400”) was mixed with 400 ml C.P. S. F. And beaten kaolin with pulp at 5% by weight and rosin size with pulp at 0.6
A paper stock was prepared by adding 2% by weight of a sulfuric acid band to 2% by weight of pulp, and 0.5% by weight of pulp to a polyamine / polyamide / epichlorohydrin resin (trade name “WS-500”) as a wet strength agent. Using a fourdrinier paper machine, base papers of various basis weights were formed according to a conventional method.

[Preparation of base paper (E)] A raw pulp composed of 25 parts by weight of NBKP, 45 parts by weight of LBKP, and 30 parts by weight of a polyethylene-based synthetic pulp (trade name "SWP E400") was mixed with 400 ml of pulp. S. F. And beaten kaolin with pulp at 5% by weight and rosin size with pulp at 0.6
A paper stock was prepared by adding 2% by weight of a sulfuric acid band to 2% by weight of pulp, and 0.5% by weight of pulp to a polyamine / polyamide / epichlorohydrin resin (trade name “WS-500”) as a wet strength agent. Using a fourdrinier paper machine, base papers of various basis weights were formed according to a conventional method.

[Preparation of base paper (F)] 25 parts by weight of NBKP and 70 parts by weight of LBKP, a composite fiber having a core-sheath structure (trade name "ES-CHOP", manufactured by Chisso Corporation), core material: polypropylene, sheath material: (Polyethylene) 5 parts by weight of a raw pulp of 400 ml C.I. S. F. And beaten kaolin to pulp at 5% by weight, rosin sizing agent to pulp at 0.6% by weight, sulfate band to pulp at 2% by weight,
Polyamine / polyamide / epichlorohydrin-based resin (trade name “WS-500”) is added as a wet paper strength enhancer to the pulp at 0.5% by weight to prepare a paper stock, and a fourdrinier paper machine is used according to a conventional method. Base papers of various basis weights were made.

[Preparation of Base Paper (G)] A raw pulp composed of 25 parts by weight of NBKP, 65 parts by weight of LBKP, and 10 parts by weight of a composite fiber having a core-sheath structure (trade name “ES-CHOP”) was mixed with 400 ml C.P. S. F. 5% by weight of kaolin with respect to pulp, 0.6% by weight of rosin sizing agent with respect to pulp, 2% by weight of sulphate band with respect to pulp, and polyamine / polyamide / epichlorohydrin resin as wet paper strength enhancer (trade name " WS-500 ") was added to pulp at 0.5% by weight to prepare a stock, and a base paper having various basis weights was formed using a Fourdrinier machine in accordance with a conventional method.

[Preparation of base paper (H)] A raw pulp composed of 25 parts by weight of NBKP and 55 parts by weight of LBKP, and 20 parts by weight of a composite fiber having a core-sheath structure (trade name "ES-CHOP") was mixed with 400 ml of pulp. S. F. 5% by weight of kaolin with respect to pulp, 0.6% by weight of rosin sizing agent with respect to pulp, 2% by weight of sulphate band with respect to pulp, and polyamine / polyamide / epichlorohydrin resin as wet paper strength enhancer (trade name " WS-500 ") was added to pulp at 0.5% by weight to prepare a stock, and a base paper having various basis weights was formed using a Fourdrinier machine in accordance with a conventional method.

[Preparation of Base Paper (I)] A raw pulp consisting of 25 parts by weight of NBKP and 75 parts by weight of LBKP was
mlC. S. F. 5% by weight of kaolin with respect to pulp, 0.6% by weight of rosin sizing agent with respect to pulp, 2% by weight of sulphate band with respect to pulp, and polyamine / polyamide / epichlorohydrin resin as wet paper strength enhancer (trade name " WS-500 ") is added to the pulp at 0.5% by weight to prepare a paper stock, and base papers of various basis weights are formed using a fourdrinier paper machine according to a conventional method, and then a thermoplastic resin dispersion ( A base paper was impregnated with “TKR-73” (trade name, modified polyvinyl acetate emulsion manufactured by Takamatsu Yushi Co., Ltd.) at 10% by weight.

[Application of Thermal Adhesive (A)] An ethylene / vinyl acetate copolymer emulsion and a wax emulsion are mixed at various mixing ratios and heat-sensitive adhesives having different melting temperatures (A1 = melting temperature 77 ° C., A2 = Melting temperature 40 ° C, A3
= Melting temperature 180 ° C.), and this was applied using a gravure coater.

[Application of Heat-Sensitive Adhesive (B)] An unsaturated polyester resin (melting temperature: 150 ° C.) was applied using a gravure coater.

[Application of Heat-Sensitive Adhesive (C)] An unsaturated polyester resin (melting temperature: 50 ° C.) was applied using a gravure coater.

[Examples 1 to 11] Table 1 shows the structures of the base paper and the heat-sensitive adhesive paper used in each example, that is, the type and basis weight of the base paper, the type of the heat-sensitive adhesive, the melting temperature, and the coating amount. , The presence or absence of irregularities on the coated surface are shown together. The unevenness of the heat-sensitive adhesive-coated surface was formed by rubbing the coated surface immediately after the coating with a wire bar (the interval between the convex portions was 0.7 mm).

[Comparative Examples 1 to 3] Table 1 shows the constitution of the base paper and the heat-sensitive adhesive paper used in each comparative example, namely, the type and basis weight of the base paper, the melting temperature of the heat-sensitive adhesive, the coating amount, and the coating amount. The presence or absence of irregularities on the surface is shown below.

[0064]

[Table 1]

Using the heat-sensitive adhesive paper shown in Table 1, the following items were evaluated. The results are summarized in Table 2. [Evaluation of anti-blocking property] Ten heat-sensitive adhesive paper samples having a size of 5 × 5 cm were stacked so that the adhesive-coated surface and the non-coated surface were sequentially overlapped, and 500 g in a thermostat at 30 ° C.
/ Cm ² , and the sample was peeled off after cooling, and the state of blocking was evaluated. The evaluation was performed according to a 5-point method. The state where no blocking occurred was evaluated as 5 points, and the state where blocking was remarkably occurred was evaluated as 1 point. Three
It is practically necessary that the number of points is equal to or more than that (the state in which blocking that would break the paper upon peeling has not occurred). Table 2
In the heat-sensitive adhesive paper of Comparative Example 2 in the middle, blocking occurred remarkably, and it was not practically usable.

[Evaluation of Performance as Adhesive Paper] Using a three-dimensional molding machine (trade name “LOM1015E”, sold by Toyota Koki Co., Ltd.) as shown in FIG.
The bonding speed was set to the values shown in Table 2, and a cubic object having a length, width, and height of 100 mm was manufactured, and the following evaluation was performed.

[Adhesiveness] The paper layer to which the molded article was adhered was peeled off by hand and evaluated by a five-point method. Five points indicate ideal adhesion, one point indicates no adhesion, and practically three or more points are required.

[Hot tack value and deformation of molded object] FIG. 2
The hot tack value of the heat-sensitive adhesive paper was measured using a heat seal tester (trade name “Heat Seal Tester TP701A”, manufactured by Tester Sangyo Co., Ltd.). The measurement conditions were as follows: the diameter of the guide roll was 20 mm, the pressure load on the upper seal bar was 1 kg / cm ² , the pressure time was 1 second, the weight W applied to the tip of the sample was 30 g, the angle θ was 20 degrees,
This is the hot tack value when the sealing temperature is [adhesive melting temperature + 30] ° C. Table 2 also shows the presence or absence of deformation of the molded article when heat-bonded under the above conditions.

[Stretching and Stretching of the Shaped Object] The obtained cubic shaped object (length, width and height are all 100 mm) is allowed to stand in a normal indoor environment (20 ° C., 40 to 60% RH) for 24 hours. The height of the molded article was Hmm. ((H-10
The value of 0) / 100) × 100 was shown as the height change rate (%) of the modeled object. This value is required to be 0.3% or less as the dimensional accuracy of the mold.

[Comprehensive Evaluation] The above items were comprehensively evaluated by a five-point method. Five points indicate no problem at all, one point indicates a remarkable defect, and practically three or more points are required.

[0071]

[Table 2]

From the results in Tables 1 and 2, the following can be understood. 1) From the comparison between each example and comparative example 1, when the base paper contains the heat-adhesive binder substance, the height change rate of the molded article is 0.3%.
The results are as follows, and it can be seen that the dimensional accuracy of the molded article is excellent even when there is a change in moisture in the air. 2) The comparison between Examples 1 to 4 and the comparison between Examples 5 to 7 show that the higher the content ratio of the heat-adhesive binder substance in the base paper, the higher the dimensional accuracy of the molded article. 3) From comparison of Examples 1-4, Examples 5-7, and Example 8, it was found that a base paper made by adding a polyethylene-based synthetic pulp to a stock as a heat-adhesive binder material was used. It can be seen that this is most suitable for improving the dimensional accuracy of the modeled object. 4) In Comparative Example 3, since the adhesive performance of the heat-sensitive adhesive paper was poor, a gap was formed between the heat-sensitive adhesive papers at the end face portion of the molded article,
It can be seen that as a result of increased absorption of moisture from the gap, the rate of change in height of the modeled object increases.

[0073]

As can be seen from the above description, according to the heat-sensitive adhesive paper for a three-dimensional molding machine of the present invention, the heat-sensitive adhesive has a heat-sensitive adhesive property that can be suitably used for a three-dimensional molding machine, and furthermore, the molded article has By absorbing and releasing moisture in the air, expansion and contraction can be effectively suppressed, and high dimensional accuracy can be provided without applying a special coating to the modeled object.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a three-dimensional molding machine for producing a three-dimensional molded object using a heat-sensitive adhesive paper.

FIG. 2 is an explanatory diagram showing the concept of an apparatus for measuring a hot tack value.

[Explanation of symbols]

 31 Thermally Sensitive Adhesive Paper 32 Vertically Movable Table 33 Supply Roll 34 Guide Roll 35 Heating Roller 36 Movable Optical Head 37 Mirror 38 Laser Light Source 39 Guide Roll 40 Winding Roll 41 Predetermined Profile 42 Cutting Line 43 Grid Cutting Wire 44 laminate

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F213 WA25 WB01 WL02 WL15 WL22 WL27 WL92 WL96 4J004 AA07 AA09 AB03 AC00 CA02 CB01 CC02 CE00 DB01 FA10 GA01 4L055 AF09 AH17 AH37 EA08 EA40 GA42

Claims (20)

[Claims] 1. A heat-sensitive adhesive paper having a heat-sensitive adhesive layer provided on a back surface is sequentially supplied to an upper surface of a vertically movable table, and the surface of the supplied heat-sensitive adhesive paper is heated while being pressed, so that the table or the table is heated. By adhering to the surface of the heat-sensitive adhesive paper that has already been supplied, a cutting line of a predetermined shape is provided on these heat-sensitive adhesive papers to form a laminate including a plurality of layers, and unnecessary portions are removed from the laminate. In a heat-sensitive adhesive paper used for a three-dimensional printing machine for obtaining a three-dimensional printing object, the melting temperature is 50 to 1
A heat-sensitive adhesive layer at 50 ° C. is provided on the back surface of a base paper having a basis weight of 40 to 200 g / m ² at 5 to 30 g / m ² , and the base paper is mainly composed of cellulose fiber and has a heat-adhesive binder substance 5 A heat-sensitive adhesive paper for a three-dimensional printing machine, characterized in that it contains about 60% by weight. 2. The hot tack value of the heat-sensitive adhesive is 30.
2. The heat-sensitive adhesive paper for a three-dimensional printing machine according to claim 1, wherein the thickness is not more than mm. 3. The base paper having a basis weight of 60 to 120 g / m ^2.
The heat-sensitive adhesive paper for a three-dimensional printing machine according to claim 1, wherein: 4. The method according to claim 1, wherein the heat-sensitive adhesive is an ethylene-vinyl acetate copolymer resin.
The heat-sensitive adhesive paper for a three-dimensional printing machine according to any one of claims 3 to 7. 5. The heat-sensitive adhesive according to claim 1, wherein the heat-sensitive adhesive is a mixture of an ethylene-vinyl acetate copolymer resin and a wax, and has a melting temperature of 60 to 90 ° C.
The heat-sensitive adhesive paper for a three-dimensional printing machine according to any one of claims 1 to 4. 6. The heat-sensitive adhesive layer is coated on the back surface of
Heat-sensitive adhesive sheet for three-dimensional modeling machine according to any one of claims 1-5, characterized in that provided 25 g / m ^2. 7. The heat-sensitive adhesive paper for a three-dimensional molding machine according to claim 1, wherein fine irregularities are formed on the surface of the heat-sensitive adhesive layer. 8. The heat-sensitive adhesive paper for a three-dimensional molding machine according to claim 7, wherein the fine uneven shape is formed by adding powder to the heat-sensitive adhesive. 9. The three-dimensional molding machine according to claim 7, wherein the fine irregularities are formed by partially changing a coating amount of the heat-sensitive adhesive layer. Thermal adhesive paper. 10. The heat-sensitive adhesive paper for a three-dimensional printing machine according to claim 1, wherein the base paper is made using a wet paper strength enhancer. 11. The heat-sensitive adhesive paper for a three-dimensional printing machine according to claim 1, wherein a moisture-proof layer is provided on the base paper. 12. The method according to claim 1, wherein a thermoplastic resin layer is provided on the surface of the base paper in an amount of 0.5 to 5 g / m ² .
The heat-sensitive adhesive paper for a three-dimensional printing machine according to any one of claims 11 to 11. 13. The method according to claim 1, wherein the melting temperature of the thermoadhesive binder material is 50 to 180 ° C.
The heat-sensitive adhesive paper for a three-dimensional printer according to any one of claims 12 to 12. 14. The heat-sensitive adhesive paper for a three-dimensional printing machine according to claim 1, wherein the heat-adhesive binder substance is a heat-adhesive fiber. 15. The heat-sensitive adhesive paper for a three-dimensional printing machine according to claim 14, wherein the heat-bondable fiber is a polyolefin-based synthetic pulp. 16. The core-sheath structure in which the heat-adhesive fiber has a core portion formed of a resin having a relatively high melting temperature or softening temperature, and a sheath portion formed of a resin having a relatively low melting temperature or softening temperature. The heat-sensitive adhesive paper for a three-dimensional printing machine according to claim 14, which is a composite fiber having the following. 17. The heat-adhesive fiber is a conjugate fiber having a side-by-side structure in which thermoplastic resins having different melting temperatures or softening temperatures are arranged in parallel along a fiber axial direction and integrated. The heat-sensitive adhesive paper for a three-dimensional printing machine according to claim 14. 18. The heat-sensitive adhesive paper for a three-dimensional molding machine according to claim 1, wherein the heat-adhesive binder material is a heat-adhesive particle. 19. The three-dimensional printing method according to claim 1, wherein the base paper is impregnated with a heat-adhesive binder substance during or after the base paper is formed. Adhesive paper for machine. 20. The heat-sensitive adhesive paper according to claim 1, which is sequentially supplied to an upper surface of a vertically movable table, and heated while pressing the surface of the supplied heat-sensitive adhesive paper. Then, the heat-sensitive adhesive paper is bonded to the table or the surface of the heat-sensitive adhesive paper that has already been supplied, and a cut line having a predetermined shape is formed on the heat-sensitive adhesive paper to form a laminate including a plurality of layers. Three-dimensional object manufactured by removing the