JP2006027182A - Manufacturing method of laminated product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a laminated product which performs the curing with certainty in a uniform cure time all the year around without being influenced by the environmental temperature of the molding site. <P>SOLUTION: In the manufacturing method of the laminated product which comprises forming a cell by disposing a female mold in a predetermined space to a thermoplastic resin molding that has beforehand been molded into a predetermined shape, supplying a polymerizable/curable resin raw material into the above cell and curing this, the method is characterized in that, when the polymerizable/curable resin raw material is supplied into the cell, the temperature of the thermoplastic resin molding is in advance maintained at a temperature selected in the range of from 30°C to the deflection temperature under load of the thermoplastic resin molding minus 40°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a laminate in which a thermoplastic resin molded article is reinforced with a cured product of a polymerization curable resin raw material.

  Conventionally, various products having a strength improved by laminating a fiber reinforced resin (hereinafter referred to as “FRP”) on the back surface of a resin molded product have been put on the market. For example, tubs and wash bowls are marketed in which a methacrylic resin having an excellent appearance is used instead of the gel coat layer as the surface layer, and the back surface is laminated and reinforced with FRP.

  For example, a resin molded product obtained by vacuum molding, pressure forming, press molding or the like often has a small thickness. In this case, the resin molded product alone cannot maintain its shape, and the strength may be insufficient at the time of use, and it becomes necessary to laminate and reinforce FRP or the like. Furthermore, since the upper limit of the use temperature is low with a resin molded product alone, the above-described lamination reinforcement is required also from that point.

  On the other hand, FRP is usually laminated by a hand lay-up method or a spray-up method, but most of this method requires manual labor and time due to manual work. In addition, since a reactive resin containing a highly harmful solvent is used, there is a problem that the working environment is poor such as evaporation of the solvent and scattering of glass fibers.

  Therefore, Patent Document 1 is disclosed as a laminate in which a resin containing a filler is filled between a vacuum-formed thermoplastic resin molded product and a mold, polymerized and cured, and integrated.

In this method, since the resin containing the filler is filled in the mold in advance, the evaporation of the solvent does not scatter to the outside air and the glass does not scatter. The bathtub can be manufactured very easily and can be operated under a good working environment.
JP-A-5-237854

  However, Patent Document 1 does not describe a temperature condition or the like of a thermoplastic resin molded product when a resin containing a filler is supplied to a cell portion, and the temperature is estimated to be a result.

  The thermoplastic resin molded body often stands by at a place close to the molding site in consideration of molding preparation work efficiency, and is almost the same temperature as room temperature.

  In such a case, the curing time until the polymerization curable resin raw material exhibits a predetermined surface hardness may depend on the temperature of the thermoplastic resin molded body.

  For example, when the polymerization curable resin raw material is supplied when the temperature is significantly lowered, the thermoplastic resin molded product can be obtained by a thermoplastic resin molded product having the same temperature as the room temperature even if the temperature of the mold is adjusted to a predetermined temperature. And the atmospheric temperature in the cell formed from the female mold will be lowered. Alternatively, when the supplied polymerization curable resin raw material and the thermoplastic resin molded product come into contact with each other, the heat of the polymerization curable resin raw material that has been temperature-controlled in advance to a predetermined temperature is taken away by the thermoplastic resin molded product. In the case as described above, the curing time may be delayed, and the laminate may be demolded in an insufficiently cured state (the insufficiently cured state here refers to zero Barcol hardness). . Since the laminate removed from the mold in the above-described state is cured without any shape restriction by the mold, the molding dimensional accuracy after curing deviates from the control range, and it is necessary to perform shape correction. Or the laminate may be discarded.

  In addition, since the laminate that is demolded in the above-described state is insufficiently cured, the surface of the laminate is easily damaged even from a small impact between demolding and curing. And often hurt. The scratch sometimes grew to a fatal crack as a product by the end of curing due to subsequent curing shrinkage or the like. Further, since stress concentrates on the scratches after curing, it may be easily cracked even with a small impact on the laminate.

  Furthermore, since the laminate that is demolded in the above-described state is in an insufficiently cured state, it takes more time to demold than the usual due to a decrease in releasability from the mold, thereby ensuring a predetermined production amount. It could be difficult. In addition, forcibly removing the mold for the convenience of production planning may cause damage to the mold that makes subsequent molding operations difficult.

  The present invention has been made to solve such problems.

  The gist of the present invention is that a cell is formed by arranging a female mold with a predetermined interval from a thermoplastic resin molded product that has been previously molded into a predetermined shape, and a polymerization curable resin raw material is supplied into the cell and cured. In the method for producing a laminate, when the polymerization curable resin raw material is supplied into the cell, the temperature of the thermoplastic resin molded product is in a range from 30 ° C. to the deflection temperature under load of the thermoplastic resin molded product of −40 ° C. It exists in the manufacturing method of the laminated body which is the state hold | maintained at the selected temperature.

  The temperature of the polymerization curable resin material and the female mold is preferably within ± 10 ° C. with respect to the temperature of the thermoplastic resin molded product.

  The manufacturing method of the present invention can be reliably cured with a uniform curing time throughout the year without being influenced by the environmental temperature at the molding site, so that workability is improved and a laminate with a desired molding dimensional accuracy is stabilized. Can be obtained.

  In addition, by setting the heating temperature of the thermoplastic resin molded product appropriately for the curing conditions of the polymerization curable resin material, it becomes possible to manipulate the curing time of the polymerization curable resin material and improve productivity. To do.

  Examples of the thermoplastic resin molded product used in the present invention include those obtained by thermoforming a resin plate such as vacuum molding, pressure forming, or press molding, and those obtained by injection molding a molding material.

  As the thermoplastic resin molded product, a molded product of a resin that can be thermoformed or injection molded, such as methacrylic resin, polystyrene resin, ABS resin, polypropylene resin, polycarbonate resin, and vinyl chloride resin, can be used. Of these, a methacrylic resin is particularly preferable because of excellent hydrolysis resistance and a small decrease in adhesion.

  The thickness of the thermoplastic resin molded product is not particularly limited, but if the thickness is too thin, cracks may occur when the solvent comes into contact, and therefore the thickness is preferably 0.3 mm or more. More preferably, it is 8 mm or more. Further, when the thermoplastic resin molded article is transparent, it may be printed on the back side or laminated with a film.

  Among these thermoplastic resin molded products, when the laminate is used in, for example, a bathtub, a wash bowl, a sink, a dressing shelf, etc., a methacrylic resin molded product excellent in hydrolysis resistance is preferable. Among the methacrylic resin molded products, a methacrylic resin plate obtained by polymerizing a polymerizable raw material consisting of methyl methacrylate alone or methyl methacrylate 60% by mass or more and acrylic ester 40% by mass or less in the presence of a polymerization initiator. What formed this is preferable. Before polymerizing the polymerizable raw material, a part of the polymerizable raw material is polymerized in advance to produce syrup which is a mixture of the polymer and the monomer, and then 0.02 to 100 parts by mass of the syrup. A methacrylic resin plate obtained by adding 1.0 part by mass of a crosslinking agent and cast-polymerizing in a mold is more preferable because of excellent thermoforming processability and solvent resistance.

  The thermoplastic resin molded product is kept at a temperature selected in advance from 30 ° C. to a deflection temperature under load of the thermoplastic resin molded product of −40 ° C. when the polymerization curable resin raw material is supplied into the cell. It is important that Preferably, it is heated in the range of 35 to 50 ° C. If the temperature of the thermoplastic resin molding is too low, the low temperature thermoplastic resin molding in the cell causes a decrease in the ambient temperature in the cell, and the polymerization curable resin raw material comes into contact with the low temperature thermoplastic molding. When it is cooled, the time required for curing becomes longer and productivity is lowered. If the temperature of the thermoplastic resin molded product is too high, the thermoplastic resin molded product is likely to be deformed when the thermoplastic resin molded product is installed in the cell or when the polymerization curable resin raw material is supplied, or the surface is damaged. It becomes easy to stick. The deflection temperature under load is obtained by measuring according to JIS K7191.

  As a method of heating a thermoplastic resin molded product, in addition to a furnace heating method and an infrared heating method, a method in which the thermoplastic resin molded product is left on a temperature-controlled male mold until it is warmed, between a temperature-controlled male and female mold A method of warming by interposing a thermoplastic resin molded product, a method of interposing a thermoplastic resin molded product between a male and female mold and leaving it in the furnace together with the mold, the female mold or the male mold And a method in which a thermoplastic resin molded article is placed in the furnace and left in the furnace until the thermoplastic resin molded article is warmed. Especially, the heating method by a furnace heating is preferable as a method which can heat the whole thermoplastic resin molded product uniformly.

  The mold used for forming the reinforcing layer for reinforcing the thermoplastic resin molded product may be a male / male mold, or the thermoplastic resin molded product is molded against the supply pressure of the polymerization curable resin. If there is no significant deformation in the product shape, the thermoplastic resin molded product itself may be used as the male mold.

  Mold materials include FRP molds using epoxy resin, vinyl ester resin, unsaturated polyester resin, etc., molds made of laminates of FRP and resin concrete, aluminum alloy molds, cast iron molds, electric molds, etc. A well-known thing can be used. In particular, the FRP mold is preferable because the mold is easy to manufacture and inexpensive.

  The female mold is provided with an inlet for supplying the polymerization curable resin into the cell. There are no particular restrictions on the installation position, number of installations, and diameter of the inlet. What is necessary is just to set suitably according to conditions, such as a magnitude | size, a shape, and supply time of a laminated body.

  It is preferable that the temperature control of the female mold is heated and held within ± 10 ° C. with respect to the holding temperature of the thermoplastic resin molded product held by heating. More preferably, it is heated and held within ± 5 ° C. If the temperature difference between the mold and the thermoplastic resin molded product is within ± 10 ° C, the time required for curing will be stable, so demolding can always be performed in a constant curing state, and a stable quality laminate will be stable. There is an advantage that it can be produced by the production amount.

  In the surface treatment of the female mold, it is preferable that the surface on the side in contact with the polymerization curable resin raw material is surface-treated in order to release the polymer curable resin raw material from the female mold easily after the polymerization curing of the polymerization curable resin raw material. In order to reduce the contact area between the female mold and the polymerization curable resin raw material, the surface roughness is preferably 25 μm or less, more preferably 6.3 μm or less. In addition, it is preferable to apply a release agent or laminate with a non-adhering material such as Teflon (registered trademark).

  In addition, the surface roughness here is the maximum height in JIS B0601; Rmax.

  When the male mold is used, it is preferable that the temperature control of the male mold is heated and held within ± 10 ° C. with respect to the holding temperature of the thermoplastic resin molded product that is heated and held. More preferably, it is heated and held within ± 5 ° C. If the temperature of the male mold is too low, the thermoplastic resin molded product held by heating is cooled by the male mold, requiring a long time for curing, resulting in a decrease in productivity. If the temperature of the male mold is too high, the thermoplastic resin molded product is likely to be deformed at the portion where it contacts the male mold, or the surface is easily damaged.

  The sealing material is a material that seals the peripheral green portion of the cell formed by the thermoplastic resin molded product and the female mold.

  Examples of the material of the sealing material include materials that do not chemically react with the bonding resin, such as a fluorine resin, a silicon resin, and an olefin resin. In consideration of reusability, a sealing material made of fluorine resin, silicon resin, or olefin resin is preferable.

  The hardness of the sealing material is not particularly limited as long as it can be easily compressed, but a sponge hardness of 30 or less is preferable.

  The cross-sectional shape of the sealing material is not particularly limited as long as it can securely seal the thermoplastic resin molded product and the female die, and may be appropriately selected.

  The void portion of the cell formed from the female mold and the thermoplastic resin molded product has the thickness of the reinforcing layer of the laminate.

  The thickness of the reinforcing layer may be uniform or non-uniform. What is necessary is just to set to the thickness which satisfies the mechanical strength required for every site | part. However, when the thickness is 2 mm or less, an unfilled portion of the polymerization curable resin raw material may occur. When the thickness is 2 mm or less, the polymerization curable resin raw material is placed in the cell using auxiliary force such as vacuum assist. It is preferable to supply to. In that case, it is necessary to separately provide a vacuum assist hole in the female mold.

  Examples of the polymerization curable resin raw material used in the present invention include unsaturated polyesters, (meth) acrylic resins, vinyl ester resins, urethane resins, epoxy resins, and resins obtained by modifying these. Unsaturated polyester resins include ortho-, iso-, tele- or bis-unsaturated polyester resins and their (meth) acryl-modified unsaturated polyester resins and ortho-, iso-, tele- or bis-unsaturated polyester resins. And an unsaturated polyester resin obtained by adding a (meth) acrylic resin. However, the polymerization curable resin raw material is not limited to these, and has an affinity with a thermoplastic resin molded product molded into a predetermined shape, and can be tightly integrated with the thermoplastic resin molded product after polymerization and curing. Anything is acceptable.

  Moreover, the polymerization curable resin raw material may contain a filler. As the filler, aluminum hydroxide, calcium carbonate, silica, glass fiber, carbon fiber, organic fiber, or the like can be used, and these can be used alone or in combination of two or more.

  Furthermore, it is preferable to include a curing agent in the polymerization curable resin raw material.

  The temperature of the polymerization curable resin raw material is preferably heated and held within ± 10 ° C. with respect to the holding temperature of the thermoplastic resin molded product that has been heated and held. More preferably, it is heated within ± 5 ° C. If the temperature difference between the polymer curable resin raw material and the thermoplastic resin molded product is within ± 10 ° C, the time required for curing will be stable, so demolding can always be performed in a constant cured state, and the quality is stable. There is an advantage that the body can be produced with a stable production amount.

  The method of heating the polymerization curable resin raw material is a method of controlling the temperature of the stored tank and piping for transporting the raw material, a method of providing a mixer section and heating by shear-heat generation by mixing, or a method of combining these two methods Etc.

  The viscosity of the polymerization curable resin raw material is preferably 100 to 8000 mPa · s when supplied to the cell portion. More preferably, it is 1000-2000 mPa * s. When it is 100 mPa · s or more, when a filler is contained in the polymerization curable resin raw material, the sedimentation rate of the filler becomes slow, and the amount of filler sedimentation in the pump or the transport pipe to the mold decreases. In addition, since the filler does not settle between the injection into the cell and the gelation, there is no uneven distribution of the filler density in the thickness direction of the reinforcing layer. Therefore, there is no deformation of the laminated body after curing due to the occurrence of a curing time difference for each part, and a laminated body with non-uniform mechanical strength is not formed.

  In addition, if it is 8000 mPa · s or less, it can be easily injected without taking time to supply and fill the cell portion, so that unfilled generation due to gelation during filling that occurs due to poor fluidity does not occur. .

  The polymerization curable resin material is supplied to the cell by pumps that are generally used for transporting the polymer curable resin material, such as gear pumps, rotary pumps, snake pumps, plunger pumps, diaphragm pumps, tube pumps, and hose pumps. As a method. As other methods, gravity is used to supply the polymerization curable resin raw material by dropping from the top of the mold, and the polymer curable resin raw material is previously placed in the female mold and the thermoplastic resin molded product is pushed in from above. The method etc. are mentioned. It is preferable to select a gear pump, a rotary pump, a snake pump, a tube pump, and a hose pump that have low pulsation in consideration of reducing the burden on the mold due to supply pressure from the pump and workability. In addition, when curing the polymerization curable resin raw material, if a curing agent is used, the discharge amount is sensed and fed back to the pump to ensure the discharge quantitativeness of the polymerization curable resin raw material and the curing agent from the pump. It is preferable to use discharge amount feedback control for controlling the amount.

  Further, there is a method of giving vibration to the cell in order to improve the filling property of the polymerization curable resin raw material in the cell. In the case of applying vibration, the vibration can be applied from the start of supply of the polymerization curable resin raw material to after the end of supply, or after a while after the start of supply.

  Further, as a method for improving the filling property, an auxiliary force such as vacuum assist may be used.

  After demolding of the cured polymer curable resin material, for example, in the case of a bathtub, it is preferable to leave the upper edge portion vertically downward and the bottom portion vertically upward. This is because if the upper edge portion is allowed to stand vertically upward, the four corners of the upper edge portion may hang vertically downward as the curing progresses, and may deviate from the management range of the bathtub product.

Moreover, in order to suppress the hardening deformation due to the progress of hardening at other portions of the upper edge, it is preferable to apply a load over the entire periphery of the upper edge after demolding. Furthermore, it is preferable to apply after-curing in the above-described state because the laminate can be completely cured.

[Example 1]
A methacrylic resin plate (trade name: Acrylite (registered trademark) PX200 (load deflection temperature 100 ° C.) manufactured by Mitsubishi Rayon Co., Ltd.) was formed into a bathtub shape by vacuum forming. 100 parts by mass of unsaturated polyester resin (trade name: Iupica 4542P, manufactured by Nippon Iupika Co., Ltd.), 150 parts by mass of calcium carbonate (product name: NS # 100, manufactured by Nitto Flour Industries) , 2 parts by mass of a curing agent (trade name: Permec Nr, 1/1 mixture of Percure AH, both manufactured by NOF Corporation) were prepared.

  As the material of the mold, a temperature-controllable FRP type made of epoxy resin was used for both male and female molds.

  The surface on the side in contact with the female-type polymeric curable resin material is processed to a surface roughness of about 6 μm by finishing with sandpaper # 800, and a release agent (trade name: Diamond Coat EZ-WAY-710, contents) : Synthetic isoparaffin hydrocarbon, aliphatic hydrocarbon, Franklin Industries, USA).

  The thermoplastic resin molded product was placed on the male mold, and the female mold was spaced about 14 mm from the bottom surface (upward) of the thermoplastic resin molded product.

  Next, the periphery of the thermoplastic resin molded product and the female mold was sealed with a silicon sponge string having a sponge hardness of 20, and pressurized from above and below with an appropriate clamping device to form a sealed cell. The temperature of the thermoplastic resin molded product in the cell was 32 ° C. by the furnace heating method, and the female mold temperature was 32 ° C. by the furnace heating method. The male mold temperature was adjusted to 31 ° C. by pouring temperature control water into a temperature control circulation pipe attached around the male mold.

  The polymerization curable resin raw material is mixed with an unsaturated polyester resin and calcium carbonate in a storage tank, adjusted to a temperature of 33 ° C. while degassing, and mixed with a curing agent and a static mixer immediately before being supplied to the cell part. The raw material was supplied to the cell formed from the thermoplastic resin molded product and the female mold as it was at 33 ° C. from the upper part of the female mold. With this supply, the air in the unfilled portion of the polymerization curable resin raw material into the cell was exhausted from the exhaust port.

  After the thermoplastic resin molded product was installed in the male mold, the installation of the female mold and the start of supplying the polymerization curable resin raw material to the mold were completed within about 3 minutes.

The polymerization curable resin raw material filled in the cell in this way is polymerized and cured for 50 minutes, then demolded, and aftercuring at 60 ° C. for 60 minutes while applying a load to the upper edge, Got a bathtub. The manufacturing conditions and evaluation results are shown in Table 1.

  All temperature units are “° C.”.

  Barcol hardness: measured in accordance with JIS K6911, using a Barcol hardness tester DYZJ934-1 type (manufactured by Barber Colmar, USA) for a total of 12 locations: 2 at the bottom, 6 at the upper edge, and 4 at the side barrel did.

  Note that the post-curing bathtub dimensional accuracy is a measurement of the warpage of the upper edge. If a ruler is placed on the upper edge and the center of the upper edge is convex, +, if the center is concave. “−”, “0” from +0 mm to −3 mm, and “x” from the others.

[Examples 2 to 4]
A resin bathtub was obtained and evaluated in the same manner as in Example 1 except that the thermoplastic resin molded article temperature, female mold temperature, male mold temperature and polymerization curable resin raw material temperature were changed to the temperatures shown in the table. The evaluation results are shown in Table 1.

[Comparative Examples 1 and 2]
A resin bathtub was obtained and evaluated in the same manner as in Example 1 except that the thermoplastic resin molded article temperature, female mold temperature, male mold temperature and polymerization curable resin raw material temperature were changed to the temperatures shown in the table. The evaluation results are shown in Table 2.

  The laminate obtained by the production method of the present invention is suitable for a bathtub, a wash bowl, a sink, a dressing shelf, a chair and the like.

Claims (2)

  In a manufacturing method of a laminate in which a cell is formed by disposing a female mold with a predetermined interval from a thermoplastic resin molded product that has been previously molded into a predetermined shape, and a polymerization curable resin raw material is supplied into the cell and cured. When the polymerization curable resin raw material is supplied into the cell, the temperature of the thermoplastic resin molded product is kept at a temperature selected in advance from 30 ° C. to a deflection temperature under load of the thermoplastic resin molded product of −40 ° C. A method for producing a laminate, characterized by being in a state.   The method for producing a laminate according to claim 1, wherein the temperature of the polymerization curable resin raw material and the female mold is within ± 10 ° C with respect to the temperature of the thermoplastic resin molded product.