JPH036455Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an SMC tray that is patterned using printed paper without distortion or tearing.

SMC is a mixture of cut glass fibers (chopped strands) in a thermosetting resin prepolymer such as unsaturated polyester resin, and is usually formed into a sheet with polyethylene film, etc. on the front and back sides when stored. It means something covered.

Moreover, the SMC tray means a tray obtained by molding the above-mentioned SMC using a mold having a desired shape.

Conventional technology Attempts have often been made to add patterns to SMC trays, including ○A method of integrating a printed film printed on plastic film such as polyvinyl chloride during molding, and ○Printing on nonwoven fabric during rotary tray molding. There are methods such as integrating the two, or using transfer printing or direct printing.

However, in method ○B above, distortion occurs at the four corners of the tray due to the stretching of the pattern, in method ○B, it is the same, and it is difficult to print clearly, and in method ○C, Because the pattern is on the surface, the pattern has insufficient solvent resistance and abrasion resistance.

Problems to be solved by the invention Therefore, the invention aims to provide an SMC tray in which the pattern is on the inside from the surface, there is no distortion at the four corners, etc., and the pattern is clear. .

Means for Solving the Problems The SMC tray of the present invention consists of a bottom part that is almost flat and has four rounded corners, and a side part connected to the bottom part and formed around the bottom part. The printing paper is laminated on either or both sides, and the angle between the bottom and side parts is
120° or more, and the inner diameter of the joint between the bottom and side surfaces is 3 mm or more.

Figure 1 is a cross-sectional view showing an example of the SMC tray of the present invention, and the SMC tray has a hardened SMC portion 2.
It consists of approximately two layers of printing paper impregnated and hardened with the thermosetting resin that constitutes SMC, and the bottom part 4
It has a structure in which the side surface portion 5 and the collar portion 6 are connected in this order. Here, the angle θ formed by the bottom surface portion 4 and the side surface portion 5 is 120° or more.

Figure 2 is a plan view of the SMC tray in Figure 1;
The four corners of the bottom part 4 are rounded, and a side part 5 is connected to the periphery of the bottom part 4, and a collar part 6 is connected to the side part 5.

In the above example, if the angle θ between the bottom part 4 and the side part 5 is 120 degrees or more, the printing paper will not be distorted or torn during molding, but it is more preferably 130 degrees or more. . However, since the side surface portion 5 also has the role of reinforcing the bottom surface portion 4,
In this sense, it is desirable that the angle θ is 140° or less. Although the collar 6 is not necessarily required, the presence of the collar 6 further strengthens the SMC tray, and
It catches your fingers when you hold it, preventing it from slipping off.
It is desirable that the angle θ formed between the flange portion 6 and the side surface portion has a value similar to the angle θ. The inner diameter of the connecting portion between the bottom part and the side part is 3 mm or more, preferably 6 mm or more. The maximum value of this inner diameter is approximately 10 mm in practice.

If the angle θ between the bottom part 4 and the side parts 5 is less than 120 degrees, or if the inner diameter of the connecting part is less than 3 mm, when the printing paper is formed into a tray shape, the bottom part 4 and the side parts 5 A large stress is applied locally to the paper at the joint. As a result, the paper does not undergo noticeable distortion like plastic film, but instead breaks down and tears occur.

The four corners of the bottom surface are preferably rounded, with a radius of 20 mm or more, more preferably 25 mm or more.

Note that the reference numeral 7 indicates a protrusion, which has a height of about 1 mm. These protrusions may be provided on the bottom surface 4, for example, in the form of dots at four locations, or may be provided as convex stripes in a substantially quadrangular shape.

The SMC tray of the present invention can be manufactured as follows.

First, the materials to be prepared are printing paper and SMC.
Printing paper base materials include thin paper for printing on building materials,
Paper reinforced paper (thin paper mixed with resin to increase the interlayer strength of the paper), transparent paper (for example, OLP manufactured by Kojin Co., Ltd.),
Paper such as titanium paper can be used as long as the resin can penetrate from the back side during SMC molding and form a resin layer that covers the printed pattern on the front side. ) is preferably 5 seconds or less.

The above paper is printed with ink prepared using a vehicle with good impregnating properties to form a printed pattern. Preferred examples of the ink vehicle used for this purpose include cellulose derivatives such as ethylcellulose, ethylhydroxyethylcellulose, cellulose acetate propionate, nitrocellulose, and cellulose acetate, and polyvinyl butyral resin.

The ink comprising the vehicle is applied to the printing paper base material by a known printing method such as gravure offset printing, lithographic offset printing, die lithography, intaglio printing, jet printing, silk screen printing, or electrostatic printing. to form a printed pattern.

In addition, as SMC, it is usually possible to use a material mainly composed of unsaturated polyester resin, to which a solution of thermoplastic synthetic resin, a filler, an internal mold release agent, a catalyst, and a thickener are added. If desired, it may be colored with a pigment or the like.

In the above, unsaturated polyester resins are bisphenol-based, orthophthalic acid-based, and isophthalic acid-based ones, and thermoplastic synthetic resin solutions have a molecular weight of styrene (monomer) to reduce curing shrinkage of molded products. A solution of about 30,000 to 50,000 polyethylene is used, and 100 to 200 mesh CaCO ₃ is used as a filler, also serving as an extender, but considering the surface finish, clay is the most usable material. Depending on the viscosity of the unsaturated polyester resin, it is about 130 to 180 parts.The internal mold release agent is organic phosphate alone or in combination with zinc stearate, and the catalyst is t-butyl peroxybenzoate, etc. Specific examples of the thickener include MgO, Mg(OH) ₂ and the like.

The printing paper and SMC prepared above are placed below the mold 7 (set so that the top surface of the tray faces downward) as shown in Figure 3.
SMC9 is stacked one after another, but the printed paper is placed with the printed pattern side facing down, and the SMC composition is fluidized by applying heat and pressure using a press, and the composition is poured into the mold. The printing paper is filled and impregnated with resin, and the whole is cured and laminated together to form a tray shape. The molding temperature, pressure and time depend on the type and composition of the SMC resin used,
Alternatively, it can be selected as appropriate depending on the size of the molded product.

Function/Effect The SMC tray of the present invention has the above structure, and since paper is used as the printing sheet to be laminated,
Even in areas where stress and deformation are locally concentrated during molding, such as the connecting part between the bottom part 4 and the side part 5, the pattern does not become deformed or distorted unlike plastic film. On the other hand, as a problem unique to paper, discontinuous defects such as tears and creases are likely to occur in areas where stress and deformation are concentrated. Yes, since the angle between the bottom and side parts is 120° or more,
The printed paper on which the pattern is printed does not tear, and as a result, it is possible to provide an SMC tray with a clear pattern without distortion of the pattern or defects such as discontinuities such as tears in appearance.

Example Transparent paper with an air permeability of 3.5 seconds (manufactured by Kojin Co., Ltd., OLP,
3 mils), a check pattern was printed using gravure printing using ink containing cellulose acetate and nitrocellulose as a vehicle to prepare printed paper.

An SMC with the following composition was prepared.

SMC composition Isophthalic acid unsaturated polyester 60 parts by weight Thermoplastic plastic solution (polystyrene with a molecular weight of 30,000 to 50,000 dissolved in styrene monomer) 40 〃 CaCO ₃ (filler) 150 〃 Zinc stearate (internal mold release agent) 4 t-Butylperoxybenzoate 1 MgO (thickener) 1 Glass fiber (based on the entire SMC) 30% by weight The above SMC and printing paper were heated at 160℃ and 100Kg/cm by the method shown in Figure 3. ^2. Under the conditions of 90 seconds, an SMC tray without pattern distortion (size and shape shown in Figures 4 and 5) was obtained.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the SMC tray of the present invention, Figure 2 is a cross-sectional view of the SMC tray of the present invention.
The figure is a plan view of the SMC tray of the present invention, FIG. 3 is a sectional view showing the manufacturing method, and FIGS. 4 and 5 are views showing the shape of the SMC tray of the embodiment.
FIG. 4 is a plan view, and FIG. 5 is a cross-sectional view. 1...SMC tray, 2...SMC, 3...SMC
Impregnated printing paper, 4... bottom part, 5... side part, 6...
...Brim portion, 7... Protrusion, 8... Printing paper, 9...
SMC.

Claims (1)

[Claims for Utility Model Registration] (1) Consisting of a substantially flat bottom part with four rounded corners, and a side part connected to and formed around the bottom part, on either the front side or the back side, or both. The printing paper is laminated together, and the angle between the bottom part and the side part is 120° or more,
SMC tray with an inner diameter of 3 mm or more at the joint between the bottom and side parts. (2) The SMC tray according to the scope of utility model registration claim (1), in which the inner diameter of the connecting part between the bottom and side parts is 6 mm or more. (3) The SMC tray according to claim 1 or 2 of the utility model registration claim, characterized in that the printing paper has an air permeability of 5 seconds or less.