JPS6149811A - Manufacture of rubber or plastic-molded article and mold therefor - Google Patents

Abstract

PURPOSE:To form file unevenness on the surface of a molded article, by making use of a mold constituted by forming synthetic resin obtained by applying the synthetic resin to the surface of a cavity of a mold body under a state wherein the surface is held at a surface temperature of 50-450 deg.C on the surface of the cavity. CONSTITUTION:A synthetic resin layer 2 is formed on the surface of a cavity of a mold body 1 which is formed on a metal and touches a rubber or plastic molding material. A cavity is formed between a top force 1b of the mold body and a bottom force 1a of the mold body and the cavity is filled with the rubber or plastic molding material 3. The surface of the mold body 1 can be either flat or uneven surface. As the synthetic resin layer formed on the mold cavity surface possesses the same strcture as a spray coating layer, fine uneveness is formed on the surface.

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing these molded products and a mold used in the method, which will be described in detail in □-4. A method that can reliably produce rubber or plastic molded products having a finely uneven surface with good air diffusion on the mold cavity surface that comes into contact with the rubber or plastic molding material and no subiculations, and □monild used for this process. Zuru. Prior art" = (7) 1 + L question - In general, Go11
Alternatively, a plastic mold is made of a metal material such as iron or aluminum, and has an inner surface (1V bit) corresponding to the outer surface of the winter or positive molded product. How to obtain a molded product with a surface bead shape or grained surface using these molds (Formation of fine irregularities on the inner surface of the molded product corresponding to the grained surface required for a molded product to be well molded) However, conventional methods that employ such fine irregularities include a method of covering one last process or a T method.
Methods such as tsuching treatment and applying a melting q.1 coating process are adopted. lno or 1no, I+ by these methods? There is a problem in that mold releasability is poor if rubber or plastic molding material adheres to the inner surface of the mold. 1) A method is adopted in which Teflon coating liquid is sprayed onto the inner surface of the mold. However, when using this method, it was not possible to obtain a molded product with a pleasant velvety surface because the Teflon coating liquid filled the uneven surface of the inner surface of the mold. Furthermore, as a mold for obtaining a molded product having a velvet-like or grained texture of 11+1, a method is known in which a Tef[1 coating layer is formed by a powder coating method. The surface of the molded rubber or plastic molded product used was good, although it had a slightly grainy surface, and the product 1iTfi ratio was low. Furthermore, when manufacturing rubber or plastic molded products using a mold, it is necessary to dissipate the air inside the mold, and for this reason molds with air holes are used. Molded products using the provided mold had problems such as molding material entering the air holes 1) and causing spills. For this reason, a mold is used to produce a molded product without scratches, and an air permeable metal or non-metal membrane is placed at the location where the air holes are formed. The air escapes to the outside through the air hole 1
! However, this method does not work well if the pores in the breathable membrane are too small, resulting in air pockets on the surface of the molded product and poor appearance due to air not passing through. If the pores of the breathable membrane are too large, molding materials such as rubber may enter the pores during pressurization during molding, resulting in clogging. A mold for forming a coating layer (Japanese Patent Application No. 1985-1985) and a mold combining a thermally sprayed coating layer and a Teflon layer (Patent Application No. 109602/1989) have been proposed, but these molds (Since it is necessary to form a thermally sprayed coating layer, the cost of this process may increase.) The present invention was developed in view of the above circumstances. With this technology, it is possible to reliably produce rubber or plastic molded products that have good air expansion on the inner surface of the mold body that comes into contact with the rubber or plastic molding material, and that have a finely uneven surface with no scratches. ,
For this reason, tie A7, anti-vibration gol\, rubber

[]-Provides a method for manufacturing rubber or plastic molded products that can be suitably used for molding rubbers, conveyor belts, flexible tubes, solid golf balls, optical foam rubber, foamed plastics, etc., and a mold used therein. The purpose is to That is, in order to achieve the above-mentioned [1], when a rubber or plastic molding material is supplied into a mold and a rubber or plastic molded product is manufactured, as a mold,
Using a mold in which the cavity surface of the mold body is maintained at a surface temperature of 50 to 450°C, a synthetic resin liquid is applied and a 1q synthetic resin layer is formed on the surface of the 4-tobity. Supplying rubber or plastic molding material to the cavity of this mold 1)
3ti. According to the present invention, a synthetic resin layer is formed by applying a synthetic resin liquid to the surface of the mold body while maintaining the cavity surface temperature of the mold body within a certain range.
As a result, this synthetic resin layer has fine irregularities and air retention ability, and therefore a rubber or plastic molded product having a finely irregular surface without spills can be reliably obtained. The present invention will be explained in more detail below. 'For W! ILIL The mold according to the present invention has a mold main body with a key of 6.
- Predetermined grooves in the range of 50 to 450℃ on the bit surface + eI lS
Insulation and heat retention r+! In step I, a synthetic resin liquid (synthetic resin dispersion or solution) is applied to the mold body surface. The resin layer is formed into fine irregularities with the desired ventilation +11 by appropriately selecting the type of synthetic resin, the i-crystalline surface of the cavity surface, etc.
q1 This allows a desired velvet-like or grained molded product to be made. That is, FIGS. 1 to 6 show examples of molds used for carrying out the present invention, in which the mold body 10 surface (made of metal and in contact with rubber or plastic molding material) is
A synthetic resin layer 2 is formed on the cavity surface. In the figure, 1a is the upper mold body, and 1b is the lower mold body. A cavity is formed between the upper mold body 1a and the lower mold body 11). It is filled with rubber or plastic molding material. Note that 4 is an intermediate layer formed between the mold body 1 and the synthetic resin layer 2 = 7
- Yes. In this case, the surface of the mold body 1 may be flat as shown in FIGS. 1 to 5, and may be uneven as shown in FIG. 6. Here, the synthetic resin layer 1T formed on the cavity surface of the mold body includes polytetrafluoroethylene, tetrafluor A loethylene/perflu A loalkyl vinyl ether copolymer, tetrafluor A loethylene/hexafluor A lopropylene Jt ffi Combined version, 7-trafluoroethylene/ethylene combination, polychlorotrifluor 1ro■
Fluororesins such as dylene, polyimide resins, polyamideimide resins, polyΔxybenzoate resins, poly:[-delzalphone resins, polyamide resins, polyJ-delT-thylketone resins, borif I-nylene 1)-ruphide resins,
Polyacrylate resin, polyethylene phthalate resin, polybutylene phthalate resin Iff''4, polyethylene-butylene phthalate resin, poly=1:silyl-1 non-resin, polyallyl ether resin, arylene isopropylidene resin , phenolic resin, epoxy resin, urethane resin, etc., or a mixture of 211 or more resins, and these resins can be combined with carbon, graphite, various ceramics, various metals, etc. powder, granular materials, fibrous materials, etc. 1) Powder materials such as fillers, cellulose and their derivatives, polymers such as polyacrylonitrile, composites of phenol resins, epoxy resins, etc., Ij: Ill-like materials, and other organic fillers are used. However, among these, fluororesin is particularly preferably used. When a fluororesin layer is formed as the synthetic resin layer, fluororesin liquid, especially Teflon coating liquid, is extremely sensitive to thermal or mechanical stimulation and easily resistant to thermal or mechanical stimulation. It is believed that a similar reduction occurs at the moment the Teflon coating liquid is released from the spray gun and adheres to the mold cavity surface, and is due to spraying the Teflon coating liquid while keeping the mold warm. Due to the mechanical stimulation caused by the instantaneous vaporization of the Teflon coating liquid, such as thermal stimulation, numerous Teflon aggregates adhere to the remold cavity surface.In this case, these Teflon Adhesion situation between agglomerates 15L There is a clear phase) t when the mold is not kept warm, and this phase η remains 1f J'jj 8 h: even after the final baking T culm. The Teflon coating layer has an appropriate amount of air layer even after baking, so it has excellent air removal ability.As a solvent for the synthetic resin liquid (dispersion liquid or solution),
Water, isopropyl alcohol, methyl ethyl quinone,
Methyl isobutyl ketone, lit M ethyl, trichloroedylene, xylene, I to luene are preferably used. The suitable temperature range for moisturizing the mold is determined by the degree of velvety or wrinkled skin necessary for product design, the composition of the synthetic resin solution, the type and particle size of the synthetic resin, etc. Mold cavity surface at 50-450℃
It is particularly preferable to maintain the temperature within the range of 80 to 350°C. In addition, when coating a synthetic resin liquid while keeping a mold warm, no special measures are required to keep the mold warm; simply applying the synthetic resin liquid to a mold that has reached a predetermined temperature is enough. An efficiency of 11 is obtained. In addition, by keeping the temperature of the mold constant during coating 11, it is possible to obtain fine irregularities that are even more uniform. There are no particular restrictions on the method of applying synthetic resin liquid to the -1-17 bits of the mold base wood, and any method such as air spray method, T-aresp1 method, electrostatic spray method, etc. can also be adopted. Synthetic 1 or 1 resin'X1-ding film 1t7 must also be -(-
) There is no limit to this, but it is possible to apply one coat to the J group [Yo! ″)～
It is 30μ, and if you apply a small coating, it will be 10071 PIIj
Hemp can be used 11 times 12 Usually 5 = 100 μ, especially 5 to 5
It is preferable to set it to 0 t, t. In addition, the drying and baking conditions after the synthetic resin liquid are dried and baked under appropriate conditions depending on the synthetic resin. The state of the r-plane (,1 must be −
There are no restrictions, and a synthetic resin layer is formed on one smooth surface. However, the cavity surface is formed into a finely uneven surface by applying a T-touching process to the cavity surface, and a synthetic resin layer is formed on this finely uneven surface. It is preferable that the synthetic resin layer of the present invention is formed on the entire cavity surface, or partially on a part of the cavity surface. It is also possible to form one layer or other intermediate layer 4 in the mold layer 17 as shown in Fig. 3, and then form the synthetic resin layer 3 of the present invention on top of that layer. can. Furthermore, a fluororesin layer can also be formed on the synthetic resin layer of the present invention by a powder coating method.・Furthermore, in the present invention, as shown in FIGS. 2 to 5, nine air holes communicating with the synthetic resin layer can be provided in the seventh field, and in some cases, a third air hole can be provided in this air hole.
A breathable membrane or the like may be provided as shown in FIGS. That is, according to the present invention, as described above, the mold body 1
By forming a synthetic resin layer 2 with ventilation 14+ in the mold, a rubber or plastic molding material is supplied into the mold.When molding a desired molded product, the air in the mold flows into the synthetic resin layer 2)J11 When the air is trapped in the two pores of the synthetic resin layer, it quickly diffuses into the entire layer (), and there are no air pockets, so it has an extremely good 91 view, and Therefore, the gas inside the mold is wrapped in the synthetic resin layer 2 and diffuses through the entire layer, creating an air pocket. If the air of 1) is reliably held within this synthetic resin layer 2, a good molded product of M, 1) IJ can be formed. It is possible to eliminate the need to form ventilation holes in the mold body 1 as shown in FIG. 1. It is also possible to do this, but the
) The ventilation holes 6 may be formed as shown in FIG. :Since the air can be discharged to the outside through the ventilation holes 5, the air inside the mold can be eliminated more easily, and molded products with better appearance can be produced. It is. Although the diameter of the vent hole 5 is not particularly limited, it is preferably 1 to 2+nyn from the viewpoint of processing J-. This J
: When the diameter of the vent hole 5 is relatively large, a breathable reinforcing layer 6 is added to the vent hole 5 to support or reinforce the synthetic resin N2 in the space between the vent holes during pressurization during molding. It is preferable to interpose it between the synthetic resin 1 and the synthetic resin decoy 2 (Figs. 3 and 4), or to insert an air permeable reinforcing material 7 into the ventilation hole 5 (Fig. 5). In this case, in the ventilation layers 6 and 1, the through holes 8 are made of metal, metal or non-metal sintered material (Fig. 3).
Examples include a metal or non-metallic plate (Fig. 4), and as the breathable reinforcing material 7, an appropriate material such as asbestos may be used.
Examples include t1 (Figure 5), but when gas is passed through 1
Any type of material that has a rough texture may be used, even if it has a relatively coarse mesh. Here, as shown in FIGS. 2 to 5 ( ), when a vent hole 5 is formed in the mold body 1 that penetrates from the mold surface to the outside where the molding material contacts, the vent hole 5 is covered. Synthetic resin layer 2
It is preferable to form this in that it does not cause spillage. In addition, when the intermediate layer 4 is formed of the fabric F of the synthetic resin FI2 as shown in FIG. 4, it is preferable that the intermediate layer 4 has good air permeability. By forming a synthetic resin layer having mold 1111 When a vent is provided below the synthetic resin layer, the gas trapped in the synthetic resin layer can be quickly released to the outside. (Nitsu-C1) A molded product with excellent appearance and no stains can be reliably obtained without forming air pockets or clogging in the molding material. A3 The molding method according to the present invention uses such a mold and supplies the molding material to the cavity ().
Molding is carried out under appropriate molding conditions depending on the molded product. It is possible to successfully mold a single-wave flexible tube, a salted golf ball, foamed rubber, and a foamed plastic molded product. The method for manufacturing these molded products from the rubber or plastic molding material of the present invention and the mold used in the method are such that the synthetic resin layer formed on the mold cavity surface melts! ) J layer 11' has the same structure as the J layer ( ), has fine irregularities formed therein, and has a suitable air phase. Therefore, it possesses excellent air exclusion ability, so especially synthetic wood l1
When a fluororesin layer is formed as the lt layer, the air expulsion effect does not deteriorate even if h11 sulfur is repeatedly applied. Furthermore, preparation of the base for the sprayed coating layer for the purpose of air exclusion can be omitted, and the efficiency of transportation is also excellent. As a result, it is possible to reliably produce a rubber or plastic molded product having a velvety or textured texture and having a fine concave curved surface without any subicules. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. = 16 − [Example 1. Comparative Example 11 The surface of a 190 x 190 x 2.3 myn iron plate (88 material) was degreased with trichlorethylene and blast-treated with #60 blasting material. This iron plate was left in an electric oven kept at 200°C for 10 minutes, then taken out and allowed to cool naturally until it reached a predetermined temperature. After checking the temperature using a surface temperature system, an undercoat liquid FK1919DR (manufactured by Daikin Industries, Ltd.) was spray applied at a -I aspray pressure of 2 to 3 kq/c++f. After drying with 90'Cr for 60 minutes, it was further baked at 380°C for 60 minutes to form a test piece (), which was ready for the divine test. The hot water temperature in Example 1 was 150°C], and the hot water temperature in Comparative Example 1 was 30°C. The results are shown in Table 1. [Examples 2 and 3. Comparative Example 21 The surface of a 190 x 190 x 2.3 fin iron plate (83 material) was degreased with trichlorethylene and blast-treated with #60 blasting material. 40 (manufactured by Showa Denko, material alumina-titania, particle size 5-25)
tt) was thermally sprayed to form a dissolvable layer with a film thickness of 40 to 60 μm. After leaving it in an electric furnace kept at 320°C for 10 minutes, it was taken out and cooled naturally until it reached a predetermined temperature. Ta. After checking the temperature with a surface thermometer, apply the undercoat liquid EK.
19190 B was spray applied at an air spray pressure of 2-3 ka/cf. After drying at 90°C for 60 minutes, the temperature was returned to room temperature, and then FEP-based topcoat liquid N1)-'2 (manufactured by Daikin Industries, Ltd., tetrafluoroethylene-hexafluoropropylene copolymer resin liquid) was applied at air spray pressure. 0.4-1.4ka
/cd spray coating.・Dry at 90℃ for 60 minutes 1
After drying, it was baked at 380° C. for 60 minutes to obtain a test piece, which was then subjected to various tests. In addition, the heat retention temperature in Examples 2 and 3 was 3C, respectively.
)0℃ and 150℃, the heat retention temperature in the case of Comparative Example 2 is 30℃
It is ℃. The results are shown in Table 1. [Example 4. Comparative Example 3] An undercoat layer was prepared in the same manner as in Example 3, and heated to 90°C.
After drying for 60 minutes at 1°C, it was left in an electric furnace kept at 200°C for 10 minutes, then taken out and allowed to cool naturally for 1° until the predetermined value of =a was reached. F groove groove with surface temperature t1
After checking 1f, apply 10 coating liquid ND-, 2 to T display FF.
Spray coated at 1/cy# from 0.4 to 1.4. ,!
')n'c for 60 minutes and then baked at 380℃ for 60 minutes to test (1).The heat retention temperature in the case of Example 4 was 150℃1 The lake retention degree in the case of Comparative Example 3 was 30 (E is 1, the results are shown in Table 1 J1゜ [Example 5] Apply the undercoat and - coating in the same manner as in Example 4.) ] After that,
It was dried at 90°C for 10 minutes and then baked at 380°C for 60 minutes to obtain a test piece. The results are shown in Table 1. [Example 6. Comparative Example 4] 190x190x2.3+nm iron plate (S S 44
) Degrease the surface with trichlorethylene, and use #60 plus 1 to 1 grade. This girl's board is 200
The samples were placed in an electric furnace kept at a temperature of 10 minutes (after repair, taken out) until they reached the specified temperature (100°C in the case of Example 6; 30°C on the lifting platform in Comparative Example 4). Cooled. After confirming Katamaro on the surface stage, apply undercoat liquid 85 ('
)-31/1. (manufactured by Deco Bonne 1) with T Aspray pressure 3
Spray coated at ~4kq/c# and dried at 80°C for 60 minutes. Furthermore, 10
After 1 minute, take it out and rinse it at the specified temperature (100℃ for Example 6, 30℃ for Comparative Example 4).
- Cool naturally until dry, then apply undercoat liquid 850-314 again in the same manner as the 11th coat and dry. Then 260℃
Baked for 60 minutes. Paint liquid 851-221 (manufactured by Dubonnet) on this undercoated iron plate.
was sprayed at 9/cd at a T aspray pressure of 2.5 to 3.5, dried at 80°C for 60 minutes, and then dried at 390°C.
A test piece was prepared by baking for 10 minutes. The results are shown in Table 1. The film thickness of the film deposited on the surface of the iron plate with the same strip 1'1 was measured using an electromagnetic film thickness meter, and this was defined as the film thickness. Ra11t4 was determined using the surface roughness tl using the K11 human stylus method. On the U rear arm - T recess a to be reduced to Fig. 7 <Dimensions 200 mynX
10 B of mold b with 200 x 8 mm >
1. Place a test piece C (dimension 1) as shown in Figure 7B in part 1
Insert 90mmX 190mmX 2, 3nnn>,
From that ten, Go/, C1-d was 1. This rubber sheet d lt shown in Figure 7C FjJ: Sea urchin bottom board 0 (brush cutter 160mm x 16(')mm x 3.2mTn) l and L board f (-4 method 160+nm
myn) is placed on the treetop, and a small plate 9 is placed in the center of this small plate f1-.
+n) are laminated, and in the center of the lower plate 0 there is an air reservoir hole h (yl method 5
mynX 5wnX 3 , 2+nyn). Next, press the rubber seal 1 (1) to transfer the air in the air trap hole ( ) of the lower plate e to the test piece C. Evaluate (). p1′ value M type ◎: Air completely disappears Ol: Air disappears but square marks remain ×: Air remains and covers I - 11 cuts in length and width at 1nnn intervals After applying cellophane tape to the surface where it was inserted, quickly pull it out 41.
It was 1. This operation was repeated 10 times. O: No peeling at all ×: More than 1 block peels Table 1 Results of Table 1! J, It is known that the tests of IQ Examples 1 to 6 exhibit a protected effect in the 1-A test and in the 7th stroke of the 11th board. In particular, in Example 1, when the heat retention effect of Lt-A was confirmed, it was confirmed that the surface resin layer had a thin layer of 3 to 5 lt and had an effect of air handling for t)-l-min. In addition, in Example 5, by shortening the drying time of the resin coating film, it can be seen that the effectiveness of coating the resin in a moist state is enhanced. 4 , Li?i 111 Explanation of the Drawings Figures 1 to 6 (respectively showing one embodiment of the mold of the present invention) +1 partially omitted sectional views, Figures 7 to 7
indicate the members used for air diffusion test I~, respectively, and 8~
C is a perspective view, and [) is a cross-sectional view of the member C. 1...Mold body, 2...Synthetic resin layer.

Claims (1)

[Claims] 1. A method for manufacturing a rubber or plastic molded product by supplying a rubber or plastic molding material into a mold, in which the cavity surface of the mold body is maintained at a surface temperature of 50 to 450°C. manufacturing a molded product by using a mold in which a synthetic resin layer obtained by applying a synthetic resin liquid to the cavity surface is formed on the cavity surface, and supplying the rubber or plastic molding material to the cavity of this mold. A method for manufacturing a spew-free rubber or plastic molded product having minute irregularities, characterized by: 2. The manufacturing method according to claim 1, wherein the synthetic resin layer is formed of a fluororesin. 3. Fine irregularities characterized by forming a synthetic resin layer on the cavity surface by applying a synthetic resin liquid to the cavity surface of the mold body while maintaining the surface temperature at 50 to 450°C. A mold for producing spew-free rubber or plastic molded products. 4. The mold according to claim 3, wherein the synthetic resin layer is made of fluororesin.