JP2003227624A - Drain pan - Google Patents

Abstract

(57) [Summary] [Problem] The dimensions are very stable for a long time,
A drain pan 50 with a small amount of warpage is obtained. SOLUTION: By using a foam molded article obtained by subjecting styrene resin pre-expanded particles produced under specific conditions to foam molding in a mold, a concave portion 51 for receiving a drain and a drain hole 5 are formed.
Oil-resistant resin sheet 5 on the surface of the foam molded body 53 provided with
In a drain pan 50 in which 4 are laminated and integrated, 5
Warpage h generated on the bottom surface when heated at 0 ° C. for 30 days can be made to be within 0.2% with respect to the unit length of the bottom surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drain pan used as a drain receiver of an air conditioner.

[0002]

2. Description of the Related Art Devices for commercial air conditioners, home air conditioners, refrigerators, refrigerated showcases, automobile air conditioners, etc.
A drain pan is provided for receiving condensed water (drain) generated during heat exchange. Since the drain often contains an oil component around the equipment, at least the surface portion of the drain pan in contact with the drain is usually made of an oil resistant material. Although a foamed resin molded body having a recess as a drain receiver and a drain drain hole may be used as a base material of the drain pan, in consideration of the above, at least the surface portion of the surface in contact with the drain is usually The oil resistant resin sheets are laminated and integrated.

2 and 3 show an example of a drain pan. This drain pan 50 has an oil-resistant resin on the surface of a foam molded body 53 as a base material having a drain receiving recess 51 and a drain drain hole 52. The sheets 54 are laminated and integrated.
As the foamed molded body 53 as a base material, strength, heat insulation properties required in an environment where the drain pan is used,
It is desirable to select the optimum one in consideration of sound insulation, etc., but in reality, a styrene-based resin foam molding having a thickness of about 10 to 30 mm is used in consideration of the manufacturing technology and manufacturing cost of the synthetic resin foam. Often.

As the oil-resistant resin sheet 54, ABS resin, PET resin, HIPS resin or the like is used, and it is 0.5 to
Vacuum molding of these resin sheets with a thickness of about 2 mm into the required shape is adhered and laminated on the surface of the foamed molded product after molding to form a drain pan, or the foamed molded product is formed in the mold by using pre-expanded particles. At the time of molding, the vacuum molded product may be mounted in a foam mold and simultaneously molded as a drain pan.

When the drain pan thus manufactured is mounted on, for example, an air conditioner for business use, the drain pan is installed on the bottom of a metal box serving as an outer shell, and heat is exchanged at a predetermined position in a concave portion inside the drain pan. After installing the air conditioner, the blower, etc., the metal lid as the outer shell is attached, and the air conditioner body is manufactured.

[0006]

A generally used styrene resin foam molding is obtained by heating expandable styrene resin particles containing an organic compound such as butane or pentane as a foaming agent with steam or the like. The pre-expanded particles are filled in the cavity of the mold for in-mold foam molding, and heated by steam or the like to foam-mold the pre-expanded particles in the mold. Since the foamed molded product produced in this manner uses butane, pentane, or the like as the foaming agent, it tends to undergo a dimensional change with time and shrink. For example, in the case of the drain pan 50 in which the oil-resistant resin sheet 54 is laminated and integrated on the surface as described above, the drain pan 50 is left in a heated state in an oven at 50 ° C. for 30 days (equivalent to one left at room temperature for about one year). At this time, due to the dimensional shrinkage of the foamed molded body 53 that is the base material, as shown in FIG. 3, a convex warp may occur on the bottom surface side by about 1% with respect to the unit length. .

When the warp occurs, there is a portion where the drain accommodated in the recess is partially retained without being discharged from the drain hole, which becomes a factor for propagation of various bacteria and generation of malodor. Also, when assembling the air conditioner body using the drain pan that has been formed for over a year, the warp of the drain pan causes the heat exchanger and the blower to interfere with the lid on the top surface during the air conditioner assembly work. There is also the problem of doing. Furthermore, since a gap is formed between the bottom of the box and the back surface of the drain pan, it may cause unnecessary noise.

In order to solve these problems, it is desired that the amount of upward warp that occurs when the drain pan is used for a long period of time is kept within 0.2% of the unit length at the use site of the drain pan. Yes, but not yet achieved. It is also possible to use a drain pan itself injection-molded with an oil-resistant resin, but this is not a practical solution because of the problem of increased weight, etc., and the manufacturing cost also increases.

On the other hand, in place of organic compounds such as butane and pentane, expandable styrenic resin particles using carbon dioxide gas as a foaming agent have been proposed (see Japanese Patent Laid-Open No. 4-351646). The carbon dioxide gas is used as the foaming agent in the molded product obtained by heating the pre-expanded particles obtained by heating the product, and the residual gas amount is small, so that the dimensional change after a long time can be suppressed. However, even in the case of this type of foam-molded product, when it is used as a base material of a drain pan in which an oil-resistant resin sheet of about 0.5 to 2 mm is laminated and integrated on the surface, it occurs when left for a long period of time. The amount of convex warpage cannot be within 0.2% with respect to the unit length of the bottom surface.

Further, in an air conditioner which is often installed indoors, a drain pan having a small content of volatile organic compounds, which is related to sick house (indoor air pollution), which has been a problem recently, is required. Has been.
The present invention has been made in view of the above circumstances, and an oil-resistant resin sheet is integrally laminated on a part or all of the surface of the foamed molded product having a drain receiving recess and a drain drain hole. The purpose of the drain pan is to reduce the amount of warpage that occurs on the bottom surface when left for a long period of time, to suppress the growth of various bacteria and the generation of bad odor due to the residual drain, and to provide an environmentally friendly drain pan. . Moreover, it aims at providing the foam molded object for drain pans as a base material used for such a drain pan.

[0011]

A drain pan according to the present invention comprises an oil-resistant resin sheet laminated integrally on part or all of the surface of a foamed molded product having a drain receiving recess and a drain drain hole. The drain pan is a foam molded product obtained by in-mold foam molding of styrene resin pre-expanded particles obtained by impregnating styrene resin particles with carbon dioxide gas, and the drain pan is dried at 50 ° C. It is characterized in that the warp generated on the bottom surface when heated for 30 days is within 0.2% with respect to the unit length of the bottom surface.

In the present invention, the condition of "heating at 50 ° C. for 30 days" is that the environment in which the drain pan is placed is normally room temperature when the air conditioner is used.
This is because the conditions of heating at 0 ° C. for 30 days are almost equivalent to the conditions of being left at room temperature for a long time (about one year).
Under that condition, the amount of warpage is "0.
If it is within 2%, it is possible to effectively solve the above-mentioned problems occurring in the drain pan.

As the oil resistant resin sheet, polyolefin resin such as polypropylene and polyethylene, A
A sheet of BS resin, PET resin, HIPS resin, polyamide resin, polyacetal resin, or the like can be used, and the thickness thereof is 0.2 to 5 mm, preferably 0.5.
It is preferably about 2 mm.

Styrene-based resin foamed molded product (that is, foamed molded product for drain pan) satisfying the above conditions.
Can be obtained by in-mold foaming of styrene resin pre-expanded particles produced as follows. That is, first, carbon dioxide gas is impregnated into styrene-based resin particles to form expandable styrene-based resin particles, and in the next step, the expandable styrene-based resin particles are charged into a pre-expanding machine equipped with a steam charging line and an exhaust line. , While supplying steam from the steam charging line at a charging pressure of 0.5 to 5.0 kg / cm ² G, exhausting the atmospheric gas containing steam from the exhaust line, and during that time, the foaming machine internal pressure from the steam charging pressure Styrene-based resin pre-expanded particles obtained by pre-expanding while maintaining a low level of 0.05 to 1.0 kg / cm ² G.

The expandable styrenic resin particles (hereinafter,
As the styrene resin particles (hereinafter referred to as “resin particles”) constituting the “expandable particles”, generally known styrene resin particles can be used. Specifically, such resin particles include styrene, α-methylstyrene, paramethylstyrene, t-butylstyrene, chlorostyrene, divinylbenzene (2
Homopolymer particles of styrenic monomers such as functional monomers) or copolymer particles combining two or more of these monomers, acrylics such as methyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, cetyl methacrylate, etc. Acid and methacrylic acid esters, or acrylonitrile, dimethyl fumarate,
Examples thereof include copolymer particles with monomers other than styrene-based monomers such as ethyl fumarate and alkylene glycol dimethacrylate (bifunctional monomer). Further, it may be resin particles obtained by extrusion blending with a resin other than the styrene resin within a range in which the styrene component in these styrene resin particles exceeds 50% by weight. Examples of the resin other than the styrene resin include a polyphenyl ether resin, a polyolefin resin, and a rubber component. In particular, polystyrene resin particles are preferable as the styrene resin particles. The particle size of the resin particles can be appropriately selected, and for example, particles having a particle size of 0.2 to 5 mm can be used.

Furthermore, it has been pointed out that volatile organic compounds may be involved in sick houses (indoor air pollution), which has recently become a particular problem, and it is desired to reduce the content thereof as much as possible. . From this viewpoint, it is preferable that the amount of residual styrene-based monomer in the resin particles is as small as possible, and the amount of styrene-based monomer contained in the resin particles is preferably 0 to 500 ppm. By using such resin particles, it is possible to obtain the foamed molded article in which the amount of the volatile organic compound is 1000 ppm or less.

In order to reduce the residual styrenic monomer in the resin particles, for example, in suspension polymerization, a high temperature initiation type polymerization catalyst of 0.05% by weight or more based on the styrenic monomer is used. The final polymerization temperature is preferably 115 ° C or higher. As the high temperature initiation type polymerization catalyst, t-butylperoxybenzoate, t-butylperoxypivalate, t-butylperoxyisopropyl carbonate,
It is particularly preferable that the temperature for obtaining a half-life of 10 hours such as t-butylperoxyacetate and 2,2-t-butylperoxybutane is 100 to 115 ° C. However,
If these are used more than necessary, decomposition by-products such as t-butanol will be contained, and therefore, depending on the type of the polymerization catalyst, the upper limit of the amount used is preferably 0.5% by weight. The molecular weight of the resin particles is preferably 200,000 to 400,000 as a weight average molecular weight measured by the GPC method. Two
If it is less than 0,000, the strength of the foamed molded product may be lowered, and if it exceeds 400,000, it is difficult to obtain sufficient foaming property, which is not preferable.

The above resin particles are impregnated with carbon dioxide gas as a foaming agent to obtain expandable particles. The carbon dioxide gas as the foaming agent may be 100% carbon dioxide gas, but other foaming agents may be added as long as the effect of the present invention is not impaired. Other blowing agents include air, inorganic blowing agents such as nitrogen, propane,
It is also possible to mix an aliphatic hydrocarbon such as butane, pentane and hexane, an alicyclic hydrocarbon such as cyclobutane, cyclopentane and cyclohexane, and an organic foaming agent such as fluorohydrocarbon. As the fluorohydrocarbon, it is preferable to use difluoroethane, tetrafluoroethane or the like, which has an ozone depletion potential of zero. Here, the organic foaming agent is preferably used in a range not exceeding 20% by weight of the total amount of the foaming agent. The content ratio of carbon dioxide gas in the expandable particles is preferably 1 to 15% by weight.

To impregnate carbon dioxide into resin particles,
For example, it can be carried out by placing resin particles in a pressure-resistant airtight container, then pressurizing carbon dioxide gas, and bringing the resin particles into contact with the pressurized carbon dioxide gas. The impregnation temperature may be increased to a temperature at which the resin particles do not coalesce with each other and agglomerate, but it is usually 0 to 40 ° C. The pressure for impregnating carbon dioxide into the resin particles is preferably 10 kg / cm ² G or more, more preferably 15 to 40 kg.
/ Cm ² G. The impregnation time can be appropriately adjusted so that the resin particles have the carbon dioxide gas content described above.
20 hours are preferable and 2-8 hours are more preferable.

When impregnating the resin particles with carbon dioxide gas,
It is preferable to apply various surface treatment agents to the surfaces of the resin particles. Examples of such a surface treatment agent include an anti-bonding agent that prevents the pre-expanded particles from bonding during heat-foaming, a fusion promoter during molding, an antistatic agent, and a spreading agent. Examples of the binding inhibitor include talc, calcium carbonate, silica, zinc stearate, aluminum hydroxide, ethylenebisstearic acid amide, tricalcium phosphate, dimethyl silicone and the like.

Examples of the fusion promoter include stearic acid, stearic acid triglyceride, hydroxystearic acid triglyceride, stearic acid sorbitan ester, and polyethylene wax. Examples of the antistatic agent include polyoxyethylene alkylphenol ether and stearic acid monoglyceride. Examples of the spreading agent include polybutene, polyethylene glycol, silicone oil and the like.

As other additives, if desired, flame retardants such as hexabromocyclododecane and tetrabromocyclooctane, methacrylic acid ester-based copolymers, ethylenebisstearic acid amide, polyethylene wax and ethylene may be added to the resin particles. -A bubble control agent such as a vinyl acetate copolymer may be contained in advance. The above-mentioned binding inhibitor, fusion promoter during molding, antistatic agent, spreading agent and other additives may be used alone or in admixture of two or more.

Further, the above resin particles preferably contain a flame retardant. As a method for obtaining resin particles containing a flame retardant, for example, in a suspension of resin particles and water, a flame retardant in the resin particles under a temperature atmosphere of the melting point or higher of the flame retardant dissolved or suspended in water. Examples thereof include a method of containing the flame retardant and a method of incorporating the flame retardant in the resin particles by extrusion blending. Examples of flame retardants that can be used at this time include hexabromocyclododecane and tetrabromocyclooctane. The flame retardant content is preferably 0.1 to 4% by weight, more preferably 0.5 to 3.0% by weight, based on the entire resin particles. When the flame retardant content is less than 0.1% by weight, it becomes difficult to obtain a sufficient flame retardant effect, which is not preferable. Further, if the flame retardant content exceeds 4% by weight, the pre-expanded particles are more likely to coalesce with each other, which is not preferable.

The pre-expanded particles are manufactured as follows. As described above, carbon dioxide gas is impregnated into styrene-based resin particles to form expandable styrene-based resin particles, and in the next step, the expandable styrene-based resin particles are placed in a pre-expanding machine equipped with a steam introduction line and an exhaust line. It is charged, and steam is supplied from the steam charging line at a charging pressure of 0.5 to 5.0 kg / cm ² G, atmospheric gas containing steam is exhausted from the exhaust line, and the pressure inside the foaming machine is charged during that time. This is a method for obtaining pre-expanded styrene resin particles by pre-expanding while maintaining the pressure lower than 0.05 to 1.0 kg / cm ² G. In this method, it is preferable to perform prefoaming immediately after the step of impregnating carbon dioxide gas.

An example of this method, that is, an example of a pre-expanding machine which can be used for producing the pre-expanded styrenic resin particles according to the present invention will be described with reference to FIG. In the figure, 1 is a pre-foaming machine, 2 is a stirring motor, 3 is a stirring blade, 4 is a baffle bar, 5 is a foaming tank upper surface detector, 6 is a foaming particle transporter, 7 is a foaming particle measuring tank, and 8 is Expandable particle injector, 9 steam injection control valve, 10 steam chamber, 11 condensed water discharge valve, 12
Is an exhaust control valve, 13 is an outlet for pre-expanded particles, 14 is a temporary receiver for pre-expanded particles, 15 is air transportation equipment, 16 is an internal pressure detection / control device, 17 is a steam injection hole, 18 is a steam injection pressure gauge, 19 Is a pressure reducing valve, and 20 is a steam source pressure gauge.

More specifically, the pressure in the pre-foaming machine 1 is controlled by the exhaust control valve 12 and the like (pressure is detected by the internal pressure detecting / controlling device 16) so that a constant amount of steam is always supplied into the pre-foaming machine 1.
Is controlled so that is always below the supply pressure. For example, the steam input pressure is 1.2 kg / cm ² G (detected by the steam input pressure gauge 18), and the pressure inside the pre-foaming machine is 0.8 kg / cm.
^When set to ² G, the pressure inside the pre-foaming machine 1 is detected by the internal pressure detection / control device 16, and the control signal is the exhaust control valve 12
Then, the pressure is controlled while releasing the pressure of 0.4 kg / cm ² G pressure from the exhaust line. In this way, the internal pressure of the pre-foaming machine 1 can be adjusted by linking and controlling the internal pressure of the pre-foaming machine 1 and the exhaust control valve 12. If the difference between the input pressure and the internal pressure of the pre-foaming machine is less than 0.05 kg / cm ² G, it will be difficult to obtain low-density pre-foamed particles, and the appearance and internal fusion of the foamed molded product will be poor, and The product value will be low. On the other hand, if it exceeds 1.0 kg / cm ² G, not only the bonding at the time of pre-foaming increases, but also the surface glossiness is low and the unevenness of the foam surface becomes large, which is not preferable. A more preferable pressure difference is 0.2 to 0.8 kg / cm ² G.

The particle size of the pre-expanded particles is 0.3 to 10 mm.
The degree of bulk density of the pre-expanded particles is 0.
It is preferably about 015 to 0.5 g / cm ³ G. And
The expandable resin particles in the pre-expanding machine are usually 110-160.
It is preferable to heat to about 0 ° C, and a more preferable heating temperature is 110 to 130 ° C. When the heating temperature is lower than 110 ° C., it is difficult to obtain pre-expanded particles having a bulk density of 0.5 g / cm ³ or less, which is not preferable. The heating temperature is 16
If the temperature exceeds 0 ° C, the pre-expanded particles tend to adhere to each other, which is not preferable.

When the oil-resistant resin sheet is laminated and integrated with the styrene resin foam molded article (that is, the foam molded article for the drain pan of the present invention) obtained by foam molding the above-mentioned pre-expanded particles, 30 at 50 ° C. The warp generated on the bottom surface of the drain pan when heated for a day can be within 0.2% with respect to the unit length of the bottom surface. The resin sheet and the foamed molded product are laminated and integrated into a desired shape,
It may be formed by adhesively laminating on the surface of the foamed molded product after molding, and when the foamed molded product is molded in-mold using the pre-expanded particles, the vacuum molded product is mounted in the foam mold and simultaneously molded as a drain pan. You may do it. Further, as described above, the content of the volatile organic compound in the foamed molded product can be set to 1000 ppm or less, and the foamed molded product according to the present invention is promising as a measure against sick house.

The overall shape of the drain pan is basically a box shape having at least a recess for receiving the drain and a drain hole, but it is not limited to this. The recess may have ribs for partitioning or reinforcing. The oil-resistant resin sheet may be laminated and integrated on the entire surface, and when the place where drainage is accumulated is limited, it may be laminated and integrated only on that region.

The foam molding method is not particularly limited, and any known method can be used. For example, pre-expanded particles are filled in a molding die and heated by steam. When the pre-expanded particles are heated by contact with steam, the pre-expanded particles expand, but the space in which the pre-expanded particles can be expanded is limited by the molding die. Can be obtained. The density of the foamed molded product (that is, the foamed molded product for a drain pan in the present invention) is preferably about 0.015 to 0.5 g / cm ³ , from the viewpoint of strength, heat insulation and sound insulation, and particularly 0.02 to It is preferably about 0.2 g / cm ³ .

[0031]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the drain pan according to the example, the vacuum-molded oil-resistant resin sheet was mounted in the foaming mold at the time of molding the foamed molded product using the pre-foamed particles, and was simultaneously molded as the foamed molding composite. In Examples and the like shown below, the warpage rate and the content of the volatile organic compound were evaluated as follows.

<Warpage Ratio> A foam molding composite body (actually, a drain pan having the shape shown in FIG. 2) taken out from the foam molding mold was placed in a constant temperature and humidity chamber (23 ° C., 50% relative humidity) (J.
After being left for 24 hours in the standard temperature and humidity of IS-K7100), a test sample according to JIS-K6767 was prepared.
After leaving this test sample in an ambient temperature of 50 ° C. for 30 days, as shown in FIG. 2, the longest diagonal line III-
The test sample was cut along the line III, placed on the surface plate 40 as shown in FIG. 3, and the distance h from the surface of the surface plate of the central portion of the sample was measured. The warpage rate K was calculated by the following formula. The measurement result was the maximum value of 10 samples.

Warp rate K (%) = (h / L) × 100
(Where L is the length of the diagonal line) <Content of volatile organic compound> After the test sample was dried in a constant temperature chamber at 50 ° C for 7 days, the values obtained by the following three types of measurement methods were summed up. I asked.

A. (Measurement of hydrocarbon having 5 or less carbon atoms) The dried test sample was put in a thermal decomposition furnace at 150 ° C., and the vaporized hydrocarbon was measured by gas chromatography. Gas chromatography (GC): Shimadzu G
C-14B Pyrolysis furnace: PYR-1A manufactured by Shimadzu Corporation Column: Porapack Q 80/100 (3 mmφ × 1.
5m) Column temperature: 100 ° C Detector (FID) temperature: 120 ° C

B. (A hydrocarbon having 6 or more carbon atoms,
Measurement of hydrocarbon up to styrene peak appearing in gas chromatogram) A test sample after drying was dissolved in dimethylformamide, an internal standard solution (cyclopentanol) was added, and measurement was performed by GC. However, peaks that could not be identified were quantified by converting to the amount of toluene detected. GC: Shimadzu Corporation GC-14A column: PEG-20M PT25% 60/80
(2.5m) Column temperature: 105 ° C Detector (FID) temperature: 220 ° C

C. (From the next peak of styrene that appears in the gas chromatogram, the carbon number is 16 (n-hexadecane).
Measurement of hydrocarbons up to) The dried test sample was dissolved in chloroform and measured with a gas chromatograph mass spectrometer (GCMS). However, a blank test was performed only with a solvent that did not dissolve the test sample, and the amount of the detected substance in the blank test was subtracted. Furthermore, peaks that could not be identified were quantified by converting to the amount of toluene detected.

GCMS: Shimadzu QP5000 column: J & W Scientific DB-1
(1 μm × 60 m 0.25 mmφ) Measurement conditions: Column temperature (after holding at 60 ° C. for 1 minute, 10
Temperature rises to 300 ° C at ℃ / min) Split ratio: 10 Carrier gas: He (1 ml / min) Interface temperature: 260 ° C

Example 1 In a 100 liter reactor, 40 kg of pure water and sodium dodecylbenzenesulfonate 2.3
g and 60 g of magnesium pyrophosphate were added to make an aqueous medium. Next, benzoyl peroxide (purity 75%) 17
44 g of styrene in which 8 g, 30 g of t-butyl peroxybenzoate and 22 g of polyethylene wax (molecular weight 1000) were dissolved was added with stirring to suspend it.
The temperature was raised to 0 ° C. to initiate polymerization. When the polymerization conversion rate measured by the specific gravity method reached 95% by weight, the temperature of the reactor was raised to 123 ° C. and held for 2 hours, then cooled to room temperature, and styrene resin particles were taken out. The residual styrene in the styrene resin particles obtained here was measured by gas chromatography and found to be 459 pm.
The weight average molecular weight measured by the method was 234,000.

Of the styrene resin particles, the particle size is from 0.7 to
After placing 15 kg of 1.0 mm in a rotary pressure-resistant container having an internal capacity of 30 liters, 7.5 g of polyethylene glycol 300 as a spreading agent, 7.5 g of glycerin monostearate and carbonic acid as a binding inhibitor. 30 g of calcium was added, the container was rotated, and it was made to adhere to the surface of the resin particle. Then, after the rotation was stopped, carbon dioxide gas was pressed into the container and kept at 25 ° C. and 30 kg / cm ² G for 6 hours to impregnate the carbon dioxide gas into the resin particles to obtain expandable styrene resin particles.

The expandable styrene resin particles thus obtained were taken out of the pressure resistant container and charged into a foaming machine equipped with a stirrer in the next step, and then steam having a charging pressure of 1.2 kg / cm ² G was introduced into the foaming machine can. . The pressure inside the foaming machine at this time was controlled to 0.8 kg / cm ² G, and while controlling the opening of the exhaust control valve with an electric signal, excess pressure was released to the outside using the exhaust line (input pressure). And the pressure inside the foaming machine is 0.4 kg / cm ² G). In this way, the steam was continuously introduced into the foaming machine and pre-expanded to obtain styrene resin pre-expanded particles. The particle size of the pre-expanded particles was 2.3 to 4.0 mm.

Six hours after the pre-foaming, the cavity shape after clamping was pre-vacuum-molded in the shape of the concave portion of the drain pan into a foam molding die designed to have the shape of the drain pan shown in FIG. A 5 mm PET molded product was fixed, and then pre-expanded particles were filled in a molding die and heated with steam to obtain a foam-molded composite (drain pan) having a shape shown in FIG. 2 (at this point, however). The drain hole 52 is not provided). The density of the foam molding is 0.020 g / cm
^{Was 3} . The warpage rate of the obtained foam-molded composite was evaluated by the above evaluation method. The results obtained are shown in Table 1.
Shown in.

Example 2 Immediately after taking out the expandable styrene resin particles from the pressure resistant container, the charging pressure was 0.85 kg /
cm ² G of steam was introduced into the foaming machine, and the pressure inside the foaming machine was adjusted to 0.8 kg / cm ² G (the difference between the input pressure and the foaming machine internal pressure was 0.05 g / cm ² G). Pre-expanded particles and a foam-molded composite were obtained in the same manner as in Example 1 except for the above. The warpage rate of the obtained foam-molded composite was evaluated by the above evaluation method. The results obtained are shown in Table 1.
The particle size of the pre-expanded particles was 2.2 to 3.6 mm, and the density of the foamed molded product portion was 0.025 g / cm ³ .

[Comparative Example 1] Immediately after taking out the expandable styrene resin particles from the pressure resistant container, the charging pressure was 2.0 kg / c.
The vapor of m ² G was introduced into the foaming machine, and the pressure inside the foaming machine was adjusted to be 0.8 kg / cm ² G (the difference between the input pressure and the pressure inside the foaming machine was 1.2 kg / cm ² G). Pre-expanded particles and a foam-molded composite were obtained in the same manner as in Example 1 except for the above. Table 1 shows the evaluation of the warpage rate of the obtained foam-molded composite. The particle size of the pre-expanded particles is 2.2 to 3.
At 6 mm, the density of the foam-molded composite is 0.025 g / cm
^{Was 3} .

[Comparative Example 2] Immediately after taking out the expandable styrene resin particles from the pressure resistant container, the charging pressure was 1.0 kg / c.
The vapor of m ² G was introduced into the foaming machine, and the pressure inside the foaming machine was adjusted to be 0.99 g / cm ² G (the difference between the input pressure and the pressure inside the foaming machine was 0.01 g / cm ² G). Pre-expanded particles and a foam-molded composite were obtained in the same manner as in Example 1 except for the above. The particle size of the pre-expanded particles is 1.5 to 2.
It was 1 mm. Table 1 shows the evaluation results of the warpage rate of the obtained foam-molded composite. The density of the foamed molded product was 0.025 g / cm ³ .

[Comparative Example 3] In a pressure vessel equipped with a stirrer having an internal volume of 5 liters, 2.0 kg of the styrene resin particles obtained in Example 1 having a particle size of 0.7 to 1.0 mm and ion-exchanged water were used. 2.2 liters, tricalcium phosphate 6.0
g, and sodium dodecylbenzene sulfonate 0.2
g was added and stirring was started. Next, after raising the temperature to 90 ° C.,
140 g of butane was pressed in and held for 5 hours. Then 3
It cooled to 0 degreeC and obtained the expandable styrene resin particle. The particles taken out were dried and then aged in a thermostatic chamber at 15 ° C. for 5 days. Zinc stearate as a binding inhibitor at the time of pre-foaming and hydroxystearic acid triglyceride as a fusion promoter are coated on the surface of the particles, and then charged into a foaming machine with a stirrer, and the pressure is 0.8 kg / cm.
² G of steam was introduced into the foaming machine. At this time, the pressure inside the foaming machine was 0.4 kg / cm ² G, and while controlling the opening of the exhaust control valve with an electric signal, the excess pressure was released to the outside using the exhaust line (the input pressure). And the pressure inside the foaming machine is 0.4 kg / cm ² G). In this way, the steam was continuously introduced into the foaming machine and pre-expanded to obtain butane-containing styrene resin pre-expanded particles. The particle size of the pre-expanded particles was 2.2 to 3.8 mm.

Six hours after the pre-foaming, the same molding die used in Example 1 was used, and the same PET molded product was fixed and foam-molded to obtain a foam-molded composite having the same shape as in Example 1. Got Table 1 shows the evaluation results of the warpage rate of the obtained foam-molded composite. In addition, the density of the foamed molded body is 0.0
It is 20 g / cm ³ .

[0047]

[Table 1]

As a result of the above, in-mold expansion-molded articles of styrene resin pre-expanded particles obtained by impregnating styrene resin particles with carbon dioxide gas, an expandable styrene-based resin having carbon dioxide gas as styrene resin pre-expanded particles A styrene-based resin foam-molded product that was foam-molded by using the pre-expanded particles by adjusting the difference between the pressure of the resin particles and the pressure inside the foaming machine was used as a base material, and a resin sheet was laminated and integrated on the surface thereof. It can be seen that the product (drain pan) has an extremely small amount of warp, and inconveniences due to accumulated drainage can be avoided. Further, the content of the volatile organic compound can be extremely reduced.

[0049]

According to the present invention, a drain pan having a configuration in which an oil-resistant resin sheet is laminated integrally on a part or all of the surface of a foamed molded product having a drain receiving recess and a drain vent hole is provided. The amount of upwardly convex warpage that occurs on the bottom surface when left for a long period of time can be reduced, and it is possible to effectively avoid the inconvenience caused by warpage, such as the propagation of miscellaneous bacteria and the generation of bad odor due to residual drainage. You can You can get a drain pan that is kind to the environment.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a pre-foaming machine used for producing styrenic resin pre-expanded particles that can be used in the present invention.

FIG. 2 is a diagram showing an example of a drain pan.

3 is a sectional view taken along the line III-III of FIG.
The method of measuring the warp rate of the drain pan shown in FIG. 2 will be described.

[Explanation of symbols]

2 stirring motor 3 stirring blades 4 baffles 5 Foam tank top detector 6 Effervescent particle transporter 7 Effervescent particle measuring tank 8 Expandable particle feeder 9 Steam injection control valve 10 Steam chamber 11 Condensed water discharge valve 12 Exhaust control valve 13 Pre-expanded particles outlet 14 Pre-expanded particle temporary receiver 15 Air transportation equipment 16 Internal pressure detection / control device 17 Steam injection hole 18 Steam input pressure gauge 19 Pressure reducing valve 20 Steam source pressure gauge 50 drain pan

Claims (3)

[Claims] 1. A drain pan in which an oil-resistant resin sheet is laminated and integrated on a part or all of the surface of a foamed molded article having a drain receiving recess and a drain drain hole, wherein the foamed molded article is a styrene type. An expanded molded article obtained by in-mold foam molding of styrene resin pre-expanded particles obtained by impregnating resin particles with carbon dioxide gas, and using a drain pan at 50 ° C.
A drain pan characterized in that the warp generated on the bottom surface when heated for a day is within 0.2% with respect to the unit length of the bottom surface. 2. Styrene-based resin pre-expanded particles used for forming a foamed molded article are expanded styrene-based resin particles obtained by impregnating styrene-based resin particles with carbon dioxide gas, and are provided with a steam injection line and an exhaust line in the next step. The expandable styrenic resin particles are charged into the pre-foaming machine, steam is supplied from a steam charging line at a charging pressure of 0.5 to 5.0 kg / cm ² G, and an atmosphere gas containing steam is discharged from an exhaust line. Styrene resin pre-expanded particles obtained by pre-expanding while evacuating and maintaining the internal pressure of the foaming machine at 0.05 to 1.0 kg / cm ² G lower than the steam input pressure during the exhaust. The drain pan according to item 1. 3. The content of volatile organic compounds is 1000 p.
It is below pm, The drain pan which consists of a styrene resin foam molding of Claim 1 or 2 characterized by the above-mentioned.