JP2010077247A - Method for producing sheet-shaped thermosetting resin molding material - Google Patents

Abstract

[PROBLEMS] To obtain a molded article having excellent appearance without surface smoothness and color unevenness when the carrier film and paste are improved in peelability and pressed into a mold for heating. A method for producing a sheet-like thermosetting resin molding material is provided.
SOLUTION: A reinforcing fiber 4 is sprayed on a compound paste 2 in which various additives are mixed with a thermosetting unsaturated polyester resin, and the impregnated molding material is sandwiched between two carrier films 7. In the method for producing a sheet-like thermosetting resin molding material, a sheet-like thermosetting resin molding material is characterized in that a hydrophilic agent 6 is applied in advance to the surface of each carrier film 7 in contact with the compound paste 2. Manufacturing method.
[Selection] Figure 1

Description

  The present invention relates to a sheet-like thermosetting resin molding material (SMC) called a sheet molding compound, and more specifically, a sheet having improved releasability between the SMC and a carrier film that sandwiches and holds the SMC in a sandwich shape. The present invention relates to a method for producing a thermosetting resin molding material.

  Conventionally, sheet-like thermosetting resin molding materials known as SMC are usually thermosetting resins such as unsaturated polyester resins, low shrinkage materials, fillers, initiators, internal mold release agents, stabilizers, and colorants. , Thickening agent and other additives are mixed into a paste, and glass fiber, carbon fiber and other reinforcing fibers are mixed between two carrier films, and a sheet of appropriate size It is manufactured by.

  FIG. 2 of the present application is an explanatory view schematically showing a conventionally known method for producing a sheet-like thermosetting resin molding material. As shown in FIG. 2, in the known manufacturing method, a pair of impregnation rollers 3 are provided at regular intervals, and the impregnation rollers 3 have the same speed in opposite directions as indicated by arrows. It is arranged to rotate at. A doctor knife 1 is provided above each of the impregnation rollers 3 so as to face each other, and the compound in which the unsaturated polyester resin, the filler, the low shrinkage material, the initiator and the like are mixed by the doctor knife 1 is a compound paste. 2 is adjusted to have a uniform thickness and supplied onto the impregnation roller 3.

  Here, the compound paste 2 has a predetermined ratio of thermosetting and liquid unsaturated polyester resin and fillers such as calcium carbonate and aluminum hydroxide, low shrinkage materials, initiators, and other additives. Thus, it is mixed in advance by a mixing means such as a mixer and stored in a paste tank (not shown) as a compound. And it supplies to the impregnation roller 3 through a supply path outside a figure.

  The compound paste 2 having a constant thickness by the doctor knife 1 is uniformly applied onto the surface of the impregnation roller 3 to form a paste film 21. Further, reinforcing fibers 4 such as glass fibers and carbon fibers are uniformly dispersed on the surface of the paste film 21.

  Thereafter, the paste film 21 and the reinforcing fiber 4 on the impregnating roller 3 pass through a narrow gap between the impregnating roller 3 and the impregnating roller 3, and pressure is applied to the reinforcing fiber 4 from both sides to form a compound. Paste 2 is impregnated. The mixture of the compound paste 2 and the reinforcing fiber 4 generated by the impregnation is scraped off by the scraper 5 and dropped, and is temporarily stored on the upper portion of the take-up roll 8 to form the impregnation B.

  On the other hand, the carrier film 7 is unwound from both the left and right, reaches the take-up roll 8 and changes its direction from horizontal to vertical. The impregnated material B formed on the upper portion of the take-up roll 8 is guided to the guide plate 9 while being sandwiched between the two carrier films 7 and shaped into a sheet, and a sheet-like thermosetting resin molding material is formed. Is obtained as product P.

  On the other hand, in JP-A-7-178729, a molding material impregnated with reinforcing fibers with a paste-like material in which a thermosetting resin and an additive such as a filler are mixed is sandwiched between two carrier films. In the method for producing a sheet-like thermosetting resin molding material comprising sandwiching between the above, another paste-like material is previously applied in a thin film form on each surface of the carrier film that contacts the molding material. A sheet-like thermosetting resin molding material and a method for producing the same are disclosed.

That is, the carrier film is peeled off by providing a thin skin layer on the inner surfaces of the two carrier films in advance with a paste prepared by mixing the same thermosetting resin as used for the molding material and an additive such as a filler. After that, a continuous layer of paste is uniformly formed on the surface of the molding material. The effect is described as being able to obtain an excellent cured molded product having a smooth surface and having no color unevenness after being cured to obtain a molded product.
JP 7-178729 A

  However, the technique described in Patent Document 1 has the following problems. That is, on the inner surfaces of the two carrier films, a paste prepared by mixing the same thermosetting resin as used for the molding material and an additive such as a filler is provided as a thin skin layer. There is a problem that the peelability between the skin layer paste and the carrier film is poor, and irregularities, pinholes, etc. are generated on the surface of the skin layer after the carrier film is peeled off.

  The sheet-shaped molding material product produced by the above method is a final molded product, for example, by peeling off the carrier films on both sides, or by laminating several sheets and then curing by pressing and heating with a mold. Although it is a bathtub, a plate material, etc., there is a problem that unevenness and pinholes generated when the carrier film is peeled remain on the surface of the final product and lead to generation of defective products.

  The present invention has been made in view of the above-mentioned background art, and its purpose is to improve the peelability between the carrier film and the paste, and press and heat with a mold to cure the final molded product. By providing a method for producing a sheet-like thermosetting resin molding material (SMC) for obtaining a final molded article having a good surface smoothness and excellent appearance without whitening, pinholes, color unevenness, etc. is there.

  In order to solve the above-mentioned problem, a manufacturing method of a sheet-like thermosetting resin molding material according to the invention described in claim 1 is a compound paste obtained by mixing various additives with a thermosetting unsaturated polyester resin. In the method for producing a sheet-like thermosetting resin molding material by spreading reinforcing fibers and sandwiching the impregnating molding material between two carrier films, the surface of each carrier film in contact with the compound paste A hydrophilic agent is applied in advance.

  As the carrier film, a film formed of a thermoplastic resin is used. For example, various thermoplastic resin films such as polyethylene, polypropylene, and polyester can be used.

  Examples of the reinforcing fiber include various inorganic fibers such as glass fiber, carbon fiber, boron fiber, and metal fiber, and various organic fibers such as vinylon and kepler.

  The method for producing a sheet-like thermosetting resin molding material according to the invention described in claim 2 is the method for producing a sheet-like thermosetting resin molding material according to claim 1, wherein the hydrophilic agent is an inorganic oxide. Or it is the diluted aqueous solution which diluted the inorganic acid with alcohol and water, It is characterized by the above-mentioned.

  Examples of the inorganic oxide include colloidal silica, and examples of the inorganic acid include nitric acid. The colloidal silica or nitric acid is diluted with alcohol and water and used as a hydrophilic agent. At this time, the coating amount on the carrier film is preferably 1.0 g / m2.

  In the method for producing a sheet-shaped thermosetting resin molding material according to the invention of claim 1, the reinforcing fiber is dispersed in a compound paste formed by mixing various additives with a thermosetting unsaturated polyester resin, and impregnated. When the molding material is sandwiched between two carrier films, the surface of each carrier film that contacts the compound paste is pre-coated with a hydrophilic agent, so a thin water film of the hydrophilic agent is formed. In addition, the interface between the carrier film and the thickening behavior of the compound paste can be easily controlled, and the carrier film can be easily peeled off.

  This water film increases the moisture content of the compound paste at the interface and lowers the tack force. Therefore, the peelability of the compound film and the interface of the carrier film is improved, and the molded product is obtained by heat curing. When this is used, it is possible to obtain a cured molded product such as an excellent bathtub or plate material having a smooth surface and no pinholes or color unevenness.

  In the method for producing a sheet-like thermosetting resin molding material according to the second aspect of the present invention, in particular, a diluted aqueous solution obtained by diluting an inorganic oxide or an inorganic acid with alcohol and water is used as the hydrophilic agent. When applied to the surface of the film in contact with the compound paste, the moisture content at the interface of the compound paste can be effectively increased, and the peelability between the carrier film and the compound paste can be further improved.

  Hereinafter, an embodiment of a method for producing a sheet-like thermosetting resin molding material according to the present invention will be described in detail with reference to the drawings. Fig.1 (a) is explanatory drawing which shows typically an example of embodiment of the said manufacturing method.

  As shown in FIG. 1 (a), a pair of impregnating rollers 3 are arranged at regular intervals, and each impregnating roller 3 is rotated at the same speed in opposite directions as indicated by arrows. ing. A doctor knife 1 is provided above each of the impregnation rollers 3. On the other hand, a non-illustrated paste tank has a predetermined amount of a thermosetting unsaturated polyester resin, a filler such as calcium carbonate and aluminum hydroxide, a low shrinkage material, an initiator, an internal release agent, a stabilizer, a colorant, A thickener or the like is charged, mixed uniformly by a mixer, and stored as a compound.

  This compound is supplied as a compound paste 2 from an unshown paste tank, adjusted to have a uniform thickness by a doctor knife 1, and supplied to a rotating roller 3. Thus, the paste film 21 having a uniform thickness is formed on the surface of the impregnation roller 3.

  On the other hand, above the impregnation roller 3, the roving of the glass fiber as the reinforcing fiber 4 is cut into a chopped strand, which is uniformly spread on the surface of the paste film 21 from an unshown spreader. Thereafter, the paste film 21 and the glass fiber on the impregnation roller 3 are impregnated with the compound paste 2 by applying pressure from both sides of the glass fiber while passing through a narrow gap between the impregnation roller 3 and the impregnation roller 3. Is done. The mixture of the compound paste 2 and the reinforcing fiber 4 generated by the impregnation is scraped off by the scraper 5 and dropped, and is temporarily stored on the upper portion of the take-up roll 8 to form the impregnation B.

  On the other hand, the carrier film 7 is unwound from both the left and right, reaches the take-up roll 8 and changes its direction from horizontal to vertical. The impregnated material B formed on the upper portion of the take-up roll 8 is guided by the guide plate 9 while being sandwiched between the two carrier films 7 and taken down. Here, before the carrier film 7 reaches the take-up roll 8, the hydrophilic agent 6 is thinly and uniformly applied on the upper surface of the carrier film 7 by the hydrophilic agent coating machine 62. The coating amount of the hydrophilic agent 6 is preferably 1.0 g / m 2 or less, and a thin hydrophilic film 61 is thus formed on the carrier film 7.

  The two carrier films 7 coated with the hydrophilic agent 6 thinly are taken up by the two take-up rolls 8 and are guided together with the guide plate 9 so as to sandwich the impregnation B in a sandwich shape. It advances between the plates 9 and is shaped into a sheet. At this time, a thin water film 61 of the hydrophilic agent 6 is formed on the two carrier films 7, and the water film 61 increases the water content of the compound paste 2 at the interface of the carrier film 7 and increases it. Increases viscosity and reduces tack. In this way, the peelability of the interface between the carrier film 7 and the paste 2 is improved, and the carrier film on both sides is easily peeled off, so that the sheet-like heat according to the present invention has no unevenness, pinholes, color unevenness, etc. on the peeled surface. A curable resin molding material is obtained as product A.

  In the present embodiment, the flow of moving the compound paste 2 vertically from top to bottom has been described as an example. However, the flow of moving the compound paste 2 from left to right or from right to left may be used. it can.

  FIG.1 (b) is explanatory drawing which shows typically the other example of embodiment of the manufacturing method of the sheet-like thermosetting resin molding material which concerns on this invention. This embodiment shows the case where the compound paste 2 is moved from left to right.

  As shown in FIG. 1B, the carrier film 7 is guided onto the belt conveyor 10 from the left end, and the hydrophilic agent 6 is sprayed onto the carrier film 7 from the hydrophilic agent coating machine 62. Next, the compound paste 2 in the dip pan 11 is applied onto the carrier film 7 with a constant thickness. Next, reinforcing fibers 4 such as glass fibers are spread on the compound paste 2.

  On the other hand, the carrier film 7 is also supplied from the right side of the belt conveyor 10. The hydrophilic agent 6 is also sprayed on the carrier film 7 from the hydrophilic agent coating machine 62 on the right side. Then, the compound paste 2 in the right dip pan 11 is applied on the carrier film 7 with a certain thickness.

  The carrier film 7 supplied from the right side is polymerized to the carrier film 7 supplied from the left side. The polymerized carrier films 7 and 7 are taken out as a finished product from the right side of the belt conveyor 10.

  Thus, the manufacturing method of the sheet-like thermosetting resin molding material according to the present invention can be changed in design, and both cases belong to the technical scope of the present invention unless departing from the scope of the claims.

(A) is explanatory drawing which shows typically an example of embodiment of the manufacturing method of the sheet-like thermosetting resin molding material which concerns on this invention, (b) is manufacture of the sheet-like thermosetting resin molding material which concerns on this invention. Explanatory drawing which shows the other example of embodiment of a method typically. Explanatory drawing which shows typically the manufacturing method of conventionally well-known sheet-like thermosetting resin molding material.

Explanation of symbols

A Sheet-like thermosetting resin molding material P obtained by the production method of the present invention Sheet-like thermosetting resin molding material B obtained by a known production method Impregnation 1 Doctor knife 11 Dip pan 2 Compound paste 21 Paste film DESCRIPTION OF SYMBOLS 3 Impregnation roller 4 Reinforcing fiber 5 Scraper 6 Hydrophilic agent 61 Water film 62 Hydrophilic agent coating machine 7 Carrier film 8 Take-up roll 9 Guide plate 10 Belt conveyor

Claims (2)

  By spreading reinforcing fibers on a compound paste made by mixing various additives with a thermosetting unsaturated polyester resin, the impregnated molding material is sandwiched between two carrier films to form a sheet-like thermoset. In the method for producing a resin molding material, a hydrophilic agent is applied in advance to the surface of each carrier film in contact with the compound paste, the method for producing a sheet-like thermosetting resin molding material.   The method for producing a sheet-like thermosetting resin molding material according to claim 1, wherein the hydrophilic agent is a diluted aqueous solution obtained by diluting an inorganic oxide or an inorganic acid with alcohol and water.

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