JP4953863B2 - Method for producing printed material of porous thermoplastic resin - Google Patents

Description

  The present invention relates to a method for producing a porous thermoplastic resin print having open cells used for an ink-embedded permeation stamp.

Porous thermoplastic resin prints having open cells are disclosed in Japanese Patent Publication Nos. 47-1173, 47-39212, and 51-74057. Further, as a method for forming a printing surface of a porous thermoplastic resin printed body, a method of forming a printing surface by selectively irradiating infrared rays (Japanese Patent Laid-Open Nos. 50-31908, 6-155698, and 10). -114132), a method of forming a stamped surface by pressing against a heated mold (Japanese Patent Laid-Open Nos. 50-155323 and 60-193686), and a method of directly engraving with a laser processing machine (Japanese Patent Laid-Open No. 10-337943) and the like are known.
Such a porous thermoplastic resin printing body can contain a large amount of ink even if it is a pigment ink having a relatively high viscosity, and boasts a good ink discharge amount.

Japanese Patent Publication No. 47-001173 Japanese Examined Patent Publication No. 47-039212 JP-A-51-074057 JP 50-031908 A Japanese Patent Laid-Open No. 06-155698 JP-A-10-114132 JP 50-155323 A JP 60-193686 A Japanese Patent Laid-Open No. 10-337943

A conventional porous thermoplastic resin printed body is a water-soluble compound particle that contributes to the formation of air bubbles and the connection path connecting the air bubbles to air bubbles, such as chlorides such as sodium chloride and sugars such as starch, and In order to uniformly disperse these, bubble forming aids such as alkylene glycol were used. However, since these bubble forming agents and bubble forming aids are hygroscopic, the size and quality of each lot are different. In contrast, the size of the bubbles and the number of connection paths (hereinafter referred to as “open cell property”) of the printed porous thermoplastic resin after production have a drawback. In addition, delicate work is required for moisture such as storage of raw materials, humidity during production, and storage of work in progress.
In the manufacturing process of porous thermoplastic resin prints, chlorides, sugars, and bubble-forming aids are washed away with water, but the waste liquid becomes a mixture of these and is difficult to reuse. There was nothing but to dispose of as industrial waste.
Accordingly, an object of the present invention is to provide a porous thermoplastic resin printing body that solves the above problems by using extremely simple raw materials.

  A method for producing a porous thermoplastic resin print obtained by removing the palatinose or reduced palatinose from a mixture of only a thermoplastic resin and palatinose, or a mixture of only a thermoplastic resin and reduced palatinose.

By incorporating palatinose or reduced palatinose as the bubble-forming agent, a porous thermoplastic resin printed body having improved cell opening properties while maintaining the uniformity of the bubbles could be obtained. Also, only palatinose or reduced palatinose is used, and no foaming aids such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, glycerin are used. In addition, it was possible to obtain a porous thermoplastic resin print having good releasability and a low defect rate.
Further, since one type of bubble forming agent is removed, a pure substance can be obtained and reused by distilling and drying the waste liquid.

Hereinafter, the material used in the present invention will be described.
The thermoplastic resin used in the present invention is polyethylene, polypropylene, polybutylene, polyurethane, poly-1,2-butadiene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-vinyl acetate copolymer, acrylic acid. Methyl ester, acrylic acid ethyl ester, acrylic acid propyl ester, acrylic acid butyl ester, polystyrene, polyvinyl chloride, polyester, polycarbonate, polyethylene-based thermoplastic elastomer, polypropylene-based thermoplastic elastomer, polybutylene-based thermoplastic elastomer, polyurethane-based thermoplastic Thermoplastics such as elastomers, polystyrene-based thermoplastic elastomers, polydiene-based thermoplastic elastomers, polychloride-based thermoplastic elastomers, ethylene vinyl acetate copolymer resins, etc. It can be used fat. The thermoplastic resin preferably has a melting point of 40 ° C to 150 ° C.
Among the thermoplastic resins, polyethylene, polypropylene, polyethylene-based thermoplastic elastomers, and polypropylene-based thermoplastic elastomers are most preferably used from the physical aspects such as weather resistance, chemical resistance, and moldability.

Next, in the present invention, palatinose or reduced palatinose having a melting point of 150 ° C. or more and a particle size of 0.1 to 500 μm is blended as a bubble forming agent.
The palatinose that can be used in the present invention refers to a palatinose produced by allowing a transferase to act on sugar, wherein α-1,2 bonds of sugar are changed to α-1,6 bonds.
The reduced palatinose that can be used in the present invention refers to a sugar alcohol produced by reducing the palatinose by hydrogenation. Α-D-glucopyranosyl-1,6-sorbitol (GPS) and α-D- It is a mixture of white and odorless crystals called glucopyranosyl-1,6-mannitol (GPM). Specifically, Paratinit (trade name: manufactured by Shin Mitsui Sugar Co., Ltd.), isomalt (trade name: Crester) and the like can be exemplified.
Palatinose or reduced palatinose is non-toxic, highly safe, and has excellent solubility in water, so it can be easily removed by water, but it has low hygroscopicity, and is a porous thermoplastic resin print. The particle size does not change during the manufacturing process, and a stable product can be obtained.
In addition, since palatinose or reduced palatinose has a melting point of 150 ° C. or higher and is solid at room temperature, a solid sheet can be obtained by kneading with a thermoplastic resin to create a solid sheet. Since there is no deformation, there is an advantage that the handling becomes simple.
The use ratio of palatinose or reduced palatinose is about 50 to 1000 parts, preferably 200 to 500 parts, relative to 100 parts of the thermoplastic resin. A particle size of 1 to 200 μm is particularly preferably used.

In the present invention, water-soluble compounds such as salts and sugars are not blended. In the present invention, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, glycerin, paraffin, wax, higher fatty acid, fluorine-based surfactant, and silicone-based surfactant. Do not use chemicals or nonionic surfactants.
However, a desired amount of a coloring agent that does not dissolve in water, such as an arbitrary pigment or dye such as carbon black, nigrosine, petal, ultramarine, or the like, can be added.

In the case of using a method for forming a stamped surface of a porous thermoplastic resin by selectively irradiating infrared rays, an additive that efficiently absorbs infrared rays is required, and carbon black that is also used as a colorant is the most Used as a preferred additive.
The use ratio of the additive is about 0.1 to 1000 parts with respect to 100 parts of the thermoplastic resin. The additive is appropriately selected depending on the application, and several types can be used in combination.

Next, a method for producing the porous thermoplastic print of the present invention will be described.
First, an additive such as palatinose or reduced palatinose and, if necessary, carbon black is added to a two-roll or kneader. Next, the thermoplastic resin in the form of chips is added and further kneaded while the temperature is not lower than the melting point of the thermoplastic resin and not higher than the melting point of palatinose or reduced palatinose. If it does so, there also exists an effect | action by pressure etc., Although all the particles of a palatinose or a reduced palatinose do not melt | dissolve, the particle | grain surface will be kneaded in the state which became slightly softened or fuse | melted.
Next, the powdered or pelletized mixture is formed into a flat plate shape with a calender roll or a press, and then air-cooled to first create a sheet body. The sheet body is in a state in which palatinose or reduced palatinose and additives are uniformly and uniformly dispersed in the thermoplastic resin, and is a solidified hard sheet body, which is pressed with fingers. It does not deform easily.
Next, after removing palatinose or reduced palatinose from the sheet body using warm water, running water or the like, this is dehydrated and dried to obtain a porous thermoplastic resin sheet body. As described above, it seems that the particle surface of palatinose or reduced palatinose is slightly softened or melted, and the softened or melted part serves as a foaming agent for connecting the particles, and the inside of the particles is not softened. Alternatively, it is inferred that the unmelted portion forms main bubbles, and this interaction forms open cells.

Next, using a known method such as laser irradiation or infrared irradiation, a stamp face was formed by engraving or melting the non-printed portion at a depth of about 0.1 to 10 mm with respect to the porous thermoplastic resin sheet body. Thereafter, it is cut into a required size to obtain the porous thermoplastic print of the present invention. Alternatively, the porous thermoplastic resin sheet body is cut to a required size and assembled to a stamp holder or the like, and then the above method is used to engrave or melt the non-printed portion to a depth of about 0.1 to 10 mm. By forming the marking surface, the porous thermoplastic printed matter of the present invention is obtained.
The porous thermoplastic printing body obtained in this way is formed with a non-porous protective coating that cannot be exuded by engraving or being melted, and an ink exuding portion in which the porous material remains, When this is impregnated with ink, the ink occlusion amount is sufficient, and a penetrating mark capable of continuous printing can be obtained.

As another production method, a porous thermoplastic printing body can be produced using a mold.
First, an additive such as palatinose or reduced palatinose and, if necessary, carbon black is added to a two-roll or kneader. Next, the thermoplastic resin in the form of chips is added and further kneaded while the temperature is not lower than the melting point of the thermoplastic resin and not higher than the melting point of palatinose or reduced palatinose. If it does so, there also exists an effect | action by pressure etc., Although all the particles of a palatinose or a reduced palatinose do not melt | dissolve, the particle | grain surface will be kneaded in the state which became slightly softened or fuse | melted.
Next, the powdered or pelletized mixture is filled into a mold engraved at a depth of about 0.1 to 10 mm mounted on an injection molding machine or a press machine to produce a relief-shaped original marking member. The original stamp member is in a state in which palatinose or reduced palatinose and additives are uniformly and uniformly dispersed in the thermoplastic resin, and is solidified and does not easily deform even when pressed with a finger. .
Next, after removing palatinose or reduced palatinose from the original stamp member using warm water, running water, etc., it is dehydrated and dried to obtain a porous thermoplastic resin print. As described above, it seems that the particle surface of palatinose or reduced palatinose is slightly softened or melted, and the softened or melted part serves as a foaming agent for connecting the particles, and the inside of the particles is not softened. Alternatively, it is inferred that the unmelted portion forms main bubbles, and this interaction forms open cells.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
Example 1
Stirring while adding 0.3 parts by weight of carbon black and 200 parts by weight of palatinose to a kneader. Next, 100 parts by weight of a polyethylene resin chip (melting point: 120 ° C.) is added and kneaded while keeping the heat at 130 ° C. If it does so, a polyethylene resin will fuse | melt and the mixture mixed uniformly will be obtained. Next, this mixture is formed into a sheet body with a calender roll and air-cooled.
Although an intermediate sheet body is created by the above procedure, the sheet body is in a state where palatinose is uniformly dispersed in the polyethylene resin sheet, and all the substances are consolidated, It becomes a black hard sheet that does not deform at all when pressed with fingers.
Next, the sheet body is washed away with running water to completely remove palatinose. And when this is dried with a dryer, the porous thermoplastic resin sheet body which has a black open cell can be obtained.
Next, on the porous thermoplastic resin sheet body, a manuscript sheet in which a character or figure to be a marking face is formed and a remaining portion are partitioned by the magnitude of infrared transmittance is overlapped, and the front side of the manuscript sheet The surface of the porous thermoplastic resin sheet body that is heated by infrared transmission is melted and solidified under the heat of carbon black mixed in the surface of the porous thermoplastic resin sheet body. A non-porous protective coating that cannot be removed was formed, and the remaining surface of the porous thermoplastic resin sheet corresponding to the portion of the original sheet having a low infrared transmittance was formed in the ink bleeding portion. Next, when this was cut | disconnected to required size, the porous thermoplastic printing body of this invention was able to be obtained.
When this porous thermoplastic printing body is used after absorbing oil-based pigment ink of 50 to 2000 mPa · S (20 ° C., 65%, 60 rpm), the ink occlusion amount is sufficient and a clear imprint that does not bleed or blur. It could be done for a long time.
Moreover, since the removed waste liquid contains only palatinose, it can be reused after distillation and drying.

(Example 2)
Stirring while adding 0.3 parts by weight of carbon black and 250 parts by weight of reduced palatinose to a kneader. Next, 100 parts by weight of a polypropylene-based thermoplastic elastomer is added and further kneaded while applying a rotational force while gradually raising the temperature to 160 ° C. If it does so, a polypropylene-type thermoplastic elastomer will also fuse | melt and the mixture mixed uniformly will be obtained. Next, this mixture is formed into a sheet body with a calender roll and air-cooled.
An intermediate sheet body is prepared by the above procedure. In the sheet body, reduced palatinose is uniformly dispersed in the polypropylene-based thermoplastic elastomer sheet, and all the substances are consolidated. Therefore, it becomes a black hard sheet that is not deformed at all even if it is pressed with fingers.
Next, the sheet body is washed away with running water to completely remove reduced palatinose. And when this is dried with a dryer, the porous thermoplastic resin sheet body which has a black open cell can be obtained.
Next, on the porous thermoplastic resin sheet body, a manuscript sheet in which a character or figure to be a marking face is formed and a remaining portion are partitioned by the magnitude of infrared transmittance is overlapped, and the front side of the manuscript sheet The surface of the porous thermoplastic resin sheet body that is heated by infrared transmission is melted and solidified under the heat of carbon black mixed in the surface of the porous thermoplastic resin sheet body. A non-porous protective coating that cannot be removed was formed, and the remaining surface of the porous thermoplastic resin sheet corresponding to the portion of the original sheet having a low infrared transmittance was formed in the ink bleeding portion. Next, when this was cut | disconnected to required size, the porous thermoplastic printing body of this invention was able to be obtained.
When this porous thermoplastic printing body is used after absorbing oil-based pigment ink of 50 to 2000 mPa · S (20 ° C., 65%, 60 rpm), the ink occlusion amount is sufficient and a clear imprint that does not bleed or blur. It could be done for a long time.
Moreover, since the removed waste liquid contains only reduced palatinose, it can be reused after distillation and drying.

(Example 3)
Stir while adding 400 parts by weight of palatinose to the kneader. Next, 100 parts by weight of a polyethylene resin chip (melting point: 120 ° C.) is added and kneaded while keeping the heat at 120 ° C. If it does so, a polyethylene resin will fuse | melt and the mixture mixed uniformly will be obtained. The mixture is then pelletized.
Next, this pellet is filled in a mold engraved at a depth of 1 mm mounted on an injection molding machine to produce a letterpress original stamp member.
The original marking member is in a state in which palatinose is uniformly dispersed in a polyethylene resin sheet, and since all the substances are solidified, it becomes a white hard material that does not deform at all even when pressed with a finger.
Next, the original marking member is washed away with running water to completely remove palatinose. And when this is dried with a dryer, the porous thermoplastic resin printing body which has a white open cell can be obtained.
When this porous thermoplastic printing body is used after absorbing oil-based pigment ink of 50 to 2000 mPa · S (20 ° C., 65%, 60 rpm), the ink occlusion amount is sufficient and a clear imprint that does not bleed or blur. It could be done for a long time.
Moreover, since the removed waste liquid contains only palatinose, it can be reused after distillation and drying.

Example 4
Stirring while adding 300 parts by weight of reduced palatinose to the kneader. Next, 100 parts by weight of a polyethylene resin chip (melting point: 120 ° C.) is added and kneaded while keeping the heat at 120 ° C. If it does so, a polyethylene resin will fuse | melt and the mixture mixed uniformly will be obtained. The mixture is then pelletized.
Next, this pellet is filled in a mold engraved at a depth of 1 mm mounted on a press molding machine to produce a letterpress-shaped original stamp member.
The original stamp member is a white hard material in which reduced palatinose is uniformly dispersed in a polyethylene resin sheet, and since all the substances are solidified, it does not deform at all even when pressed with a finger. .
Next, the original marking member is washed away with running water to completely remove the reduced palatinose. And when this is dried with a dryer, the porous thermoplastic resin printing body which has a white open cell can be obtained.
When this porous thermoplastic printing body is used after absorbing oil-based pigment ink of 50 to 2000 mPa · S (20 ° C., 65%, 60 rpm), the ink occlusion amount is sufficient and a clear imprint that does not bleed or blur. It could be done for a long time.
Moreover, since the removed waste liquid contains only reduced palatinose, it can be reused after distillation and drying.

Claims (1)

  A method for producing a porous thermoplastic resin print obtained by removing the palatinose or reduced palatinose from a mixture of only a thermoplastic resin and palatinose, or a mixture of only a thermoplastic resin and reduced palatinose.