KR20030078192A - Unsaturated polyester resin composition for valve coating and method of coating valve with the composition - Google Patents

Abstract

PURPOSE: An unsaturated polyester resin composition for metal member mold coating, a metal member product mold coated with the composition and a method for mold coating the metal member with the composition are provided, to improve the heat resistance, the chemical resistance, the moldability and the low shrinkage. CONSTITUTION: The unsaturated polyester resin composition comprises 100 parts by weight of an unsaturated polyester resin; 20-30 parts by weight of polystyrene; 1-3 parts by weight of t-butyl peroxybenzoate as a curing agent; 240-260 parts by weight of aluminum hydroxide as a filler; 5-15 parts by weight of zinc stearate as a releasing agent; and 80-90 parts by weight of glass fiber. Preferably the unsaturated polyester resin is a terephthalic acid-based resin; the aluminum hydroxide has an average particle size of 3-10 micrometers; and the glass fiber is a chop strand glass fiber with a size of 4-10 mm.

Description

Unsaturated polyester resin composition for valve molding coating, valve molding coating method using the composition, and molded article {UNSATURATED POLYESTER RESIN COMPOSITION FOR VALVE COATING AND METHOD OF COATING VALVE WITH THE COMPOSITION}

The present invention relates to an unsaturated polyester composition having excellent heat resistance, chemical resistance, and moldability, and having low shrinkage. More specifically, the present invention relates to an unsaturated polyester composition that can be used by molding into a valve member used in a chemical process or by coating a valve member. The present invention relates to an unsaturated polyester resin composition, a method of molding coating the composition, and a product to which the composition is molded coating.

Conventional valves, particularly those used in chemical plants, are used in harsh environments at high temperatures and pressures, and at the same time are exposed to strong acids and alkalis. Therefore, the inside of the cast valve body is coated with rubber or Teflon, or manufactured and inserted into the same shape as the inside of the body by using ceramic or stainless steel to withstand high temperature, high pressure and chemicals.

However, the rubber coating has a weak defect in high temperature and acid, and the ceramic insert has a weak defect in handling due to easy breakage, and the stainless steel has a weak defect in acid, abrasion resistance and expensive, and coated with Teflon. It has the drawback of weak wear resistance.

Therefore, the invention of a new material for forming and coating parts such as valves exposed to chemicals and the inside of the valve body with a high temperature, high pressure, acid resistance, alkali resistance and wear resistance is required, and the development of a coating method thereof is required. have.

Thermosetting resins are known to be excellent in heat resistance, chemical resistance and wear resistance. The thermosetting resin is a solid at room temperature, but when heated, fluidity occurs and reactions occur between molecules to increase molecular weight, or even when in a liquid state, when a promoter and a curing agent are added to form a three-dimensional network structure. When it becomes a three-dimensional network structure, even if it heats, it will not melt but will be in the state which does not melt | dissolve in any solvent. Since this curing reaction is irreversible, it is mainly used as a material that requires thermal stability and chemical stability. Among the thermosetting resins, unsaturated polyester resins have good heat resistance, chemical resistance, and moldability, and thus are used in various industries such as automobiles, ships, construction, and electricity.

However, what kind of component is suitable for the harsh environment such as high temperature, high pressure, strong acid, etc. like the valve used in chemical plants, and it is closely related to steel, so it can be used stably without change in temperature change. Nothing is used.

The material to protect the valve by coating on the valve is to be equipped with: 1) able to withstand high temperature and high pressure; 2) easy to coat or form; 3) have chemical resistance and wear resistance; and 4) adhesion to iron. Good things are required.

In addition, there is no commercially known method for molding coating an unsaturated polyester resin composition that satisfies the above properties directly onto a valve.

An object of the present invention is the unsaturated polyester resin composition for valve coating that satisfies the conditions as described above, and can be used for a long time by coating the parts in direct contact with the chemical, such as the inside of the valve body used in the chemical factory to protect the valve and The present invention provides a valve coating method using the composition, and a product molded by the method.

1 is a process chart for molding coating the resin composition according to the invention on the valve body

2 is a perspective view illustrating a state in which the resin composition according to an embodiment of the present invention is molded coated on the valve body;

Figure 3 is a perspective view of a mold for valve forming coating according to an embodiment of the present invention

4 is a perspective view of a valve body molded coated with the composition according to the present invention;

5 is a perspective view of a pump housing and an impeller molded coated with the composition according to the present invention;

In order to achieve the above object, the present invention (a) 100 parts by weight of unsaturated polyester resin, (b) 20 to 30 parts by weight of polystyrene as a low shrinkage agent, (c) t-butyl peroxybenzoate 1 to 3 as a curing agent (D) 240 to 260 parts by weight of aluminum hydroxide as a filler, (e) 5 to 15 parts by weight of zinc stearate as a releasing agent, and (f) 80 to 90 parts by weight of glass fiber. To provide.

In addition, the unsaturated polyester resin composition for metal member coating according to the present invention, the glass fiber is a glass chop strand (chop strand) within the range of 4 mm to 10 mm, the average particle size of the aluminum hydroxide ranges from 3 ㎛ to 10 ㎛ It is characterized by being mine.

In addition, the polyester resin of the unsaturated polyester resin composition for metal member coating according to the invention is characterized in that the resin of the telephthalic acid series.

In another aspect, the present invention includes a metal member molded coating product made by heating and curing the composition.

In another aspect, the present invention is a method of molding coating a resin composition, the method comprising the steps of: heating a metal member to be coated with an unsaturated polyester resin composition and a mold movably mounted to a press to mold the composition to a predetermined temperature; Mounting the metal member on a press, treating a mold release agent on the molding surface of the mold, and forming a portion on which the resin composition of the metal subsidiary mounted on the press is to be coated and formed on the metal member or the mold to which the resin composition is to be injected. Assembling and closing the mold except the inlet, the step of injecting a predetermined amount of the resin composition into the inlet, and press the mold for molding with the inlet at a certain temperature at a certain pressure for a predetermined time to the surface of the metal member Characterized in that it comprises the step of integrally coating the composition injected into the Provided is a method of molding coating an unsaturated polyester resin composition on a metal member.

In addition, the method of molding coating the resin composition according to the present invention is a predetermined temperature for heating the metal member and the mold is 120 to 150 ℃, a predetermined time for pressing the mold is characterized in that 15 to 40 minutes.

Unsaturated polyester resin composition for metal member molding coating according to the present invention is 100 parts by weight of unsaturated polyester resin, 20 to 30 parts by weight of low shrinkage agent, 1 to 3 parts by weight of hardener, 240 to 260 parts by weight of filler, 5 to 15 parts by weight of release agent Part, 80 to 90 parts by weight of glass fiber.

The unsaturated polyester resin is prepared by condensation polymerization esterification of polybasic acids such as maleic anhydride and anhydrous polyhydric alcohols such as glycerin. Generally as said polybasic acid component, unsaturated polybasic acids, such as maleic anhydride and a fumaric acid, and saturated polybasic acids, such as phthalic anhydride, an isophthalic acid, terephthalic acid, are used, The said polyhydric alcohol component is propylene glycol, ethylene glycol, diethylene glycol, Dipropylene glycol and the like are used. In particular, the unsaturated polyester resin used in the present invention is preferably of the telephthalic acid (TPA) type.

Such unsaturated polyester resins generally exhibit a large shrinkage when cured and, when molded or coated according to this shrinkage, of glass fibers used for cracking, layering, surging and reinforcing the product. Phenomena such as embossing are likely to occur. Therefore, the low shrinkage agent is blended to prevent problems due to shrinkage. As the low shrinkage agent, polystyrene, polyurethane, acrylic, or the like is used. Especially in this invention, it is preferable to use a polystyrene dispersion liquid.

In general, silica, titanium dioxide, alumina, calcium carbonate, talc and the like are known as inorganic fillers, but the inorganic fillers used in the present invention are preferable in terms of aluminum hydroxide wear resistance and chemical resistance. In particular, the average particle size of the aluminum hydroxide used in the present invention is preferably within 3 ㎛ to 15 ㎛, more preferably within 5 ㎛ to 10 ㎛.

As the curing agent, t-butyl peroxy benzoate (TBPB), t-butyl peroxyoctoate (TBPO), t-hexyl peroxyoctoate (THPO) and the like can be used. In this invention, it is preferable to use t-butyl peroxy benzoate (TBPB).

Glass fiber is used as the reinforcing material, and generally chop strands having a diameter of 8 µm to 15 µm and a length ranging from 4 mm to 12 mm are used. Preferably, the strand is in the range of 6 mm to 8 mm.

Moreover, the mold release agent represented by zinc stearate and calcium stearate is added. Preferably, zinc stearate is preferably used in the present invention.

Dye is added to add color as needed. The amount of dye added is preferably in the range of 1 to 3 parts by weight.

In the unsaturated polyester resin composition for metal member molding coating of the present invention, a bulk molding compound (BMC) is obtained by kneading, impregnating, and aging the above components by conventional means.

The molded article of the resin composition according to the present invention is molded by heating and compressing an unsaturated polyester resin composition containing the above components at a predetermined temperature and a predetermined pressure.

The metal member to be molded and coated with the composition according to the present invention is a metal such as steel, cast iron, or stainless steel. It is preferable that the resin composition of this invention is molded-coated to iron subtitles, such as steel and cast iron.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to an accompanying drawing, the method of carrying out the molding coating of the resin composition by this invention to a metal member is demonstrated.

1 is a process chart showing a process of forming and coating a BMC, which is a resin composition according to the present invention, on a valve body, and FIG. 2 is a perspective view showing a state of forming and coating a resin composition on a valve body according to an embodiment of the present invention. 3 is a perspective view of a mold for valve forming coating according to an embodiment of the present invention.

As shown in Fig. 1, the metal member to be molded coated and the mold heating step 10, the metal member press mounting step 20, the mold forming surface release agent applying step 30, and assembling the mold with the metal member It consists of a step 40, a resin composition (BMC) input step 50, a mold pressure heating step 60, and a mold separation step 70.

As shown in Fig. 2, the mold for forming and coating the resin composition on the body 100 of the diaphragm valve includes a pair of side mounting molds 200 and 400 installed to prevent inlet and outlet of the diaphragm valve. The upper mounting mold 300 is inserted into the diaphragm seating portion to be molded, and the upper mounting mold 300 is inserted into the diaphragm seating hole to heat and pressurize the resin composition into the valve body. Molded coating on. Therefore, the mold has a structure capable of filling all of the valve body except for a space for molding coating the resin composition on the valve body.

FIG. 3 shows that heaters 210, 310, and 410 for heating the molds are inserted into the molds, respectively, in the molds for forming and coating the resin on the valve body.

In the present invention, the molding coating of the resin composition on the metal member means coating the surface of the predetermined portion of the metal member with a predetermined thickness, and means pressing molding using a mold as a coating method. . The difference between this method and injection molding is that the molding is coated on the surface of the metal member to be a product. In addition, the difference from the simple coating is that the resin composition is press-contacted using a mold.

In step 10 of heating the mold and the metal member to be molded coated with the resin composition, the mold is heated by heat by electric resistance in a state where it is mounted on a press. The metal member to which the resin composition is to be molded coated, for example the body of the diaphragm valve or the impeller or housing of the pump, is heated in an electric heater device and then mounted in a press. At this time, it heats enough time for all the parts to reach uniform temperature to 120-150 degreeC. As a plurality of molds, as shown in Figure 2, a suitable number of molds may be used depending on the shape of the metal material. When molding the interior of the diaphragm valve body 100 as shown in FIG. 2, the side mounting molds 200 and 400 and the upper openings of the valve body 100 to block both ends of the valve body 100 are formed. The upper installation mold 300 to prevent the need. That is, the number of molds is determined by the shape in which the resin composition is to be molded coated. In this case, the molds 200 and 300 may be coupled to be movable on the press, and the mold 300 is fixedly coupled to the press to function to press during molding.

In the step 20 of mounting the metal member to the press, it is preferable to use a jig for mounting the metal member 100. Such jig can be selected according to the shape of the metal member.

The application of the release agent to the molding surface of the mold is intended to facilitate separation of the molded mold from the coated surface.

After applying the release agent, the molds 200 and 400 are assembled so as to surround the portion to be molded coated with the resin composition of the metal member. At this time, the resin composition (BMC) is assembled except the inlet portion to be injected.

Next, the resin composition is introduced into the inlet formed in the mold or the product, and the mold 300 is inserted into the inlet to be heated and pressurized. Upon pressurization, the mold is heated for about 15 to 40 minutes depending on the thickness of the resin being coated while maintaining the temperature at 120 to 150 ° C.

Next, when the mold is separated, the resin composition is integrally formed and coated on the inner surface of the metal member.

4 is a perspective view of a valve body 100 molded coated with a composition according to the present invention. 4 shows that the resin composition is molded-coated only on the valve body, but a part such as a diaphragm, which is in contact with a fluid such as a chemical agent, can also be molded-coated with the resin composition.

5 is a perspective view of a housing and an impeller of a pump molded and coated with the composition according to the present invention. In order to carry out the molding coating of the housing and the impeller with the resin composition of the present invention, a mold having a shape different from that of the mold for molding coating the inside of the valve body is required. Such a shape change of the mold will be apparent to those skilled in the art, and a mold design of a suitable shape will be possible without departing from the technical scope of the present invention. For example, after preparing an upper mold and a lower mold capable of accommodating an impeller, which is a metal member, and forming an inlet for injecting the composition into a part of the upper mold, a predetermined amount of the resin composition is introduced into the inlet, and then the It is possible to design a mold that can be heated and pressurized with the mold. As described above, even when the metal part to be molded coated is changed, the method of forming and coating the composition of the present invention enables molding and coating of the resin composition on the metal member.

The unsaturated and polyester composition according to the present invention has excellent heat resistance, chemical resistance (acid and alkali resistance), and wear resistance when molded, and is used as a member of a valve used in a chemical plant, or coated on a valve member for a long time. It is possible.

In addition, the method of molding the unsaturated polyester composition for valve coating of the present invention is difficult to coat the interior due to the complex shape, such as a valve, or to produce a coating or molding of a product that is difficult to process a mold because of a small amount of production economically It provides the advantages.

An embodiment of the present invention described above and illustrated in the drawings should not be construed as limiting the technical spirit of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical spirit of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

Claims (7)

Unsaturated polyester resin composition for metal member molding coating comprising the following components: (a) 100 parts by weight of unsaturated polyester resin (b) 20 to 30 parts by weight of polystyrene as a low shrinkage agent (c) 1 to 3 parts by weight of t-butyl peroxybenzoate as a curing agent (d) 240 to 260 parts by weight of aluminum hydroxide as a filler (e) 5 to 15 parts by weight of zinc stearate as a releasing agent (f) 80 to 90 parts by weight of glass fiber The metal member molding coating of claim 1, wherein the glass fiber is a chop strand in a range of 4 mm to 10 mm, and the average particle size of the aluminum hydroxide is in a range of 3 μm to 10 μm. Unsaturated polyester resin composition. The unsaturated polyester resin composition for forming a metal member of claim 1 or 2, wherein the unsaturated polyester resin is a telephthalic acid-based resin. A metal member product molded and coated with the unsaturated polyester resin composition for molding coating according to any one of claims 1 to 3. Heating the metal member to which the unsaturated polyester resin composition is to be molded coated, and a mold movably mounted to a press to mold the composition to a predetermined temperature; Mounting the heated metal member to a press; Treating a mold release agent to the molding surface of the mold; Assembling and closing the mold, except for the metal member to which the resin composition is to be put or the injection hole formed in the mold, to close the portion to which the resin composition of the metal subsidiary mounted on the press is coated; Injecting a predetermined amount of the resin composition into the inlet; Pressing the mold for molding to a predetermined time at a predetermined pressure at a predetermined temperature to the inlet to form an integral polyester coating coating the injected composition on the surface of the metal member to an unsaturated polyester resin composition to a metal member Method of molding coating. The method of claim 5, wherein the unsaturated polyester resin composition is (a) 100 parts by weight of unsaturated polyester resin, (b) 20 to 30 parts by weight of polystyrene as a low shrinkage agent, (c) t-butyl peroxybenzoate 1 as a curing agent To 3 parts by weight, (d) 240 to 260 parts by weight of aluminum hydroxide as a filler, (e) 5 to 15 parts by weight of zinc stearate as a release agent, and (f) 80 to 90 parts by weight of glass fibers. A method of molding coating a resin composition on a metal member. The method of claim 6, wherein the predetermined temperature for heating the metal member and the mold is 120 to 150 ℃, the predetermined time for pressing the mold is 15 to 40 minutes, molding the unsaturated polyester resin composition to the metal member How to coat.