JP2003191256A - Wiping cleaner and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiping cleaner having an improved mechanical strength, such as a flexural strength, as a hard foamed plastic and also having a structure of a homogeneous three-dimensional netlike skeleton and a method of manufacturing the same, by injecting an intentionally controlled melamine foam material into a molding tool having an internal contour shape conforming with the external contour shape of the wiping cleaner to be obtained and by foaming it under volumetric restriction to make it have a desired density. <P>SOLUTION: The wiping cleaner which has the external contour shape conforming with the internal contour shape of the molding tool 12 and which is constituted of the homogeneous three-dimensional netlike skeleton of a melamine resin and has the density set to be 30-140 kg/m<SP>3</SP>and the flexural strength set to be at least 0.1 MPa or above is obtained by injecting the melamine foam material M in a quantity controlled intentionally into the required molding tool 12 and by foaming it under the volumetric restriction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiping cleaning tool and a method for manufacturing the same, and more specifically, it is preferably used as a wiping cleaning tool for cleaning the kitchen and automobiles.
Injecting the melamine foam raw material intentionally controlled into a mold having an inner contour shape that matches the outer contour shape of the wiper to be obtained, and having a desired density, and
The present invention relates to a wiping / cleaning tool having improved mechanical strength as a rigid foamed plastic such as bending strength, and a method for producing the wiping / cleaning tool.

[0002]

2. Description of the Related Art Generally, in the production of a foam made of a melamine resin, formaldehyde and an additive such as a foaming agent, a catalyst and an emulsifier are blended and sufficiently mixed with melamine which is a main raw material to foam into a desired shape. It is carried out by curing after molding.

The melamine foam obtained by the above-mentioned production method is formed from a fine three-dimensional network structure skeleton, and the skeleton is exfoliated into particles during the work such as wiping, thereby exhibiting appropriate hardness and brittleness. Since it has physical properties, it can be expected to have a good polishing action and scraping property, and can be suitably used as the “wiping cleaning tool” disclosed in Japanese Patent Application Laid-Open No. 11-128137 filed by the applicant of the present application. The above-mentioned "wiping cleaning tool" can be expected to have a sufficient dirt removing effect in dry wiping and a good cleaning effect in which the trace of wiping in the presence of water is inconspicuous due to its excellent polishing action and scraping property.

[0004]

However, the "wiping cleaning tool" described in the above-mentioned Japanese Patent Laid-Open No. 11-128137 has the following problems. That is, when the density is about 20 kg / m ^3, the skeleton structure such as melamine foam that constitutes the “wiping cleaner” becomes rough and mechanical strength such as tear strength is poor, and as a result, when continuously used with a strong force. Shape defects such as tearing will occur. Since melamine foam obtained by so-called slab foaming in a free rise or open state is used as the material, when a foam having a density of about 20 kg / m ³ is produced, it is obtained due to its foaming mechanism ([0005] described later). The density varies greatly depending on the part of the foam, and if only the part of homogeneous and high density is selected as a product,
Since there are many parts that have not reached the specified density, it is necessary to discard the excess ends after cutting. In this case, discarding causes a loss that cannot be avoided in terms of material, and there is a concern that the manufacturing cost will deteriorate. In addition, there is also a problem that some cutting mistakes affect the shape of other final products and the yield is deteriorated.

The foaming mechanism of the melamine foam by the above-mentioned slab foaming will be described with reference to FIG. 7, wherein hydrofluoroether (boiling point 60
Foaming aid such as (° C.) and water (boiling point 100 ° C.) that acts as a foaming agent and a solvent start vaporization by microwave irradiation (see FIG. 7A). The gas generated by the vaporization expands (foams) the melamine foam raw material from the inside (see FIG. 7B). With the progress of this expansion (Fig.
(See (c)), the temperature in the raw material of the melamine foam is also sequentially increased, whereby the condensation reaction of the methylolmelamine resin is started. From the stage where the blowing agent such as the hydrofluoroether having a low boiling point is completely gasified, the curing reaction of the skeleton formed by the conventional foaming starts to proceed with the expansion of the vaporized water. The curing reaction of the skeleton progresses with the foaming due to the gasification of water, and finally the gasification of the water ends, and the curing reaction reaches the end point, and the cell film formed between the skeletons vaporizes. It is destroyed by a foaming agent. A further rise in temperature starts due to the disappearance of the evaporate, and the obtained skeleton is cured (Fig. 7 (d)).
reference).

As can be seen from the above-mentioned foaming mechanism of the melamine foam raw material, the size and the like of the obtained skeleton are mainly determined by the amount of gas generated and the like. That is, if the generation of gas is biased, the foaming proceeds only in one part and the other part has a non-homogeneous skeleton structure in which sufficient foaming is not performed (see FIG. 7D). That is, the density distribution structure of the obtained melamine foam also becomes inhomogeneous.

In addition to the slab foaming, a method has also been proposed in which, after obtaining a predetermined melamine foam, the foam is subjected to press molding to increase the density and mechanical strength. However, in this case, since the melamine resin as a raw material itself has thermal properties, that is, thermosetting and high heat resistance, it is difficult to perform the press molding and the product thickness is limited, so that it is not suitable for mass production. There wasn't.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks inherent in the conventional wiping / cleaning tool, and has been proposed in order to solve the problem. By injecting a melamine foam raw material controlled intentionally into a mold having an internal contour shape matching the shape, and foaming under a volume restriction to a desired density,
An object of the present invention is to provide a wiping / cleaning tool having a uniform three-dimensional network skeleton structure and a method for manufacturing the same, while improving mechanical strength as a hard foamed plastic such as bending strength.

[0009]

[Means for Solving the Problems] In order to overcome the above-mentioned problems and achieve the intended purpose, a wiping and cleaning device according to the present invention comprises:
By deliberately injecting a controlled amount of melamine foam raw material into a required mold, and foaming under a volume restriction, an outer contour shape that matches the inner contour shape of the mold,
It is characterized in that it is composed of a homogeneous three-dimensional network skeleton of melamine resin, its density is set to ³⁰ to 140 kg / m ³ , and its bending strength is set to at least 0.1 MPa or more.

In order to overcome the above-mentioned problems and achieve the intended purpose, a method for manufacturing a wiping cleaning tool according to another invention of the present application is to inject a melamine foam raw material into a required molding die, and subject it to a volume restriction. To obtain a foamed molded product having an outer contour shape that matches the inner contour shape of the molding die, and intentionally controlling the amount of the melamine foam raw material injected into the molding die at this time. Then, the density of the obtained foamed molded article is set in the range of ³⁰ to 140 kg / m ³ , and the bending strength is set to at least 0.1 MPa or more.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a wiping / cleaning tool and a method for manufacturing the same according to the present invention will be described below with reference to the accompanying drawings with reference to preferred embodiments. The inventor of the present application provides a base material made of a melamine resin foam (hereinafter, referred to as melamine foam) with a water-soluble resin containing a required coloring material and drying it to easily obtain a desired color. It has been found that a wiping and cleaning tool that is colored in a color and has improved skeletal strength of the substrate can be obtained.

A wipe cleaning tool 1 according to a preferred embodiment of the present invention
As shown in FIG. 1, 0 is composed of a melamine foam obtained by foaming a melamine resin, and a melamine foam raw material M as a raw material is injected into a molding die 12 described later, and the raw material M is It is obtained by foaming the molding die 12 under the limited volume.

The obtained wiping / cleaning tool 10 comprises the mold 1 described above.
By setting the volume of 2 and the melamine foam raw material M to be injected, the density is set to ³⁰ to 140 kg / m ³ , preferably 40 to 120 kg / m ³ . If the density is less than 30 kg / m ³ , the skeletal structure is inferior in mechanical strength as a rigid foamed plastic such as bending strength due to the low density, and as a result, it is torn when excessive force is applied to remove severe dirt. And other shape defects will occur. On the other hand, when the density exceeds 140 kg / m ³ , the hardness becomes high contrary to the above-mentioned low density, and there is a concern that the object to be cleaned such as a gas range which is hard to be scratched may be damaged by abrasion (hardness). Regarding, there is a positive correlation with the bending elastic modulus described later, and the bending elastic modulus is 50 MPa.
It is empirically known that the effect will increase if the value exceeds the limit).

In particular, bending strength is mentioned as a physical property of a hard body which is expected to be improved depending on the density. This bending strength has a great influence on the handleability when the wiping / cleaning tool 10 is used in an actual wiping operation with the hand. It has been empirically known that when the bending strength does not reach at least 0.1 MPa or more, there is a problem that the handling property is poor and the wiping operation cannot be sufficiently performed in actual use. This bending strength is specified in JIS K 7221 "Bending test method for rigid foam plastics".

In addition to the bending strength, the physical properties of the hard body are as follows.
Similarly, the flexural modulus (MPa) specified in JIS K 7221 "Bending test method for rigid foamed plastics",
The compressive strength (kPa) specified in JIS K 7220 “Compression test method for hard foamed plastics” may be mentioned. Particularly, regarding the compressive strength, the shape retention in actual use, that is, the ease of use is directly related. Is an important factor to do. Further, these physical property values basically improve in proportion to the value of the density, and if the density is 30 kg / m ³ or more, no problem occurs.

The wiping / cleaning tool 10 is specifically manufactured by a manufacturing apparatus 30 as shown in FIG. The manufacturing apparatus 30 uses a foaming solvent, a foaming auxiliary agent, an emulsifier, a surfactant, a pH adjusting agent, etc., a foaming solvent such as pentane, and a curing catalyst such as formic acid, which are required for the main raw material melamine resin. Is mixed and kneaded in the required amount to obtain a melamine foam raw material M, and a raw material adjusting / kneading section 32 and the kneaded melamine foam raw material M are weighed and poured into a molding die 12 having a desired internal contour shape, and microwaved. It is basically composed of an injection / foaming section 40 which is foamed / cured by irradiation or the like to obtain a wiping / cleaning tool 10 having an outer contour shape that matches the inner contour shape of the mold 12.

The surfactant also plays a role as a foam stabilizer and / or an emulsifier during foaming. On the other hand, when it becomes the wipe cleaning tool 10 to be obtained,
The wiping / cleaning tool 10 remains in the system as it is.
When used, it also acts as a so-called soap as a cleaning component.

Therefore, it can be used for imparting a chemical cleaning effect to the wiping / cleaning tool 10 in addition to the physical wiping action. In order to expect a sufficient cleaning action, it is necessary to mix at least 20 parts by weight with respect to 100 parts by weight of the melamine resin which is the main raw material, and the skeleton of the wiping cleaning tool 10 that can be obtained with such an amount of mixing. It is known that the state, that is, the foaming state is also stable.

If the amount of the surfactant mixed is less than 20 parts by weight, the chemical detergency is deteriorated, but the skeleton (foaming) state of the wipe cleaning tool 10 obtained above is deteriorated and the bending strength is increased. It also adversely affects the physical properties such as. On the other hand, the upper limit of the mixing amount can be up to about 100 parts by weight with respect to 100 parts by weight of the melamine resin as the main raw material, and the larger the mixing amount, the better the chemical detergency. However, if the mixing amount exceeds 100 parts by weight, the cells between the skeletons of the foam constituting the obtained wiper are filled,
It should be noted that there are problems that the scraping action is reduced, the surface of the wiping cleaning tool becomes slippery, the handling property is greatly deteriorated, and the bending strength is reduced even if the density is the same.

The surfactant also has the function of making the obtained wiping / cleaning tool 10 compatible with water, that is, improving the swelling property. Therefore, the larger the mixing amount, the more suitable the method of using, for example, car washing of an automobile using water.

The raw material adjusting / kneading section 32 mixes all the raw materials required for manufacturing the wiping / cleaning tool 10,
Further, it is a portion to be kneaded uniformly, and specifically, a single-screw or twin-screw extruder, a kneader, a pressure kneader, a co-kneader,
Banbury mixer, Henschel type mixer, rotor type mixer, pin mixer or homogenizer and other kneading machines 34
Etc. are preferably used. No special device is required for this kneading, and the kneading speed is not limited. The temperature and time at the time of kneading depend on the physical properties of the above-mentioned objects to be mixed, but it is sufficient that the objects are sufficiently mixed and kneaded. Further, in consideration of handling a liquid substance such as a melamine aqueous solution, a liquid mixing tank 36 may be provided in addition to the kneading machine 34 and the like. Since the pH adjuster has an action of delaying the reaction and curing of the mixture after mixing and kneading, depending on the mixing and kneading time here and the injection time into the molding die 12 which will be described later,
The amount to be added is appropriately changed before use.

The injecting / foaming section 40 is used for adjusting the raw material.
The melamine foam raw material M obtained in the kneading section 32 is a portion for obtaining the wiping cleaning tool 10 which is an expanded molded body having an outer contour shape that matches the inner contour shape of the molding die 12. Arranged in line,
A transfer means 42 such as a belt conveyer for transferring the molding die 12 by a driving source (not shown), and a foaming / curing process which is arranged in the middle of the transfer path of the transportation means 42 and is irradiated with microwaves to the entire molding die 12 being transferred. Basically, it comprises a foaming / drying means 44 having a heating mechanism 44a capable of performing drying. Further, when the obtained wiping / cleaning tool 10 is dried, as will be described later, since by-products such as moisture and toxic formaldehyde are generated at the time of foaming, a discharge device (not shown) for removing them by suction, for example. Is provided. Regarding the heating mechanism 44a, its type, number, arrangement position and the like are appropriately determined depending on the size of the foamed material and the like.

The mold 12 is basically openable and closable,
In addition, it is composed of two upper and lower halves 12a, 12a that define an inner contour shape that matches the outer contour shape of the wiping cleaning tool 10 that should be obtained inside when closed, and its required position is at the time of foaming / drying described later. A plurality of discharge holes 12b for discharging moisture and formaldehyde vapor, which are foaming by-products generated in the above, to the outside are provided. The volume of the molding die 12 is smaller than the foaming volume when the melamine foam raw material M to be injected is free rise, that is, slab foamed. This is the density (A) of the foam obtained by so-called molding using the required molding die 12.
Is to expand the same amount of foaming material in the open state, that is, to make it larger than the density (B) of the foam that is slab-foamed, and the pack rate = (A) / (B) is 1 or more. Refers to something.

The material of the mold 12 is preferably selected according to the heating mechanism 44a of the foaming / drying means 44 described above. For example, when microwave irradiation is adopted as the foaming / drying means 44, the melamine foam raw material M into which the microwave irradiation is injected is used.
In order to efficiently reach the mold, a material having a small dielectric loss coefficient such as engineering plastic, ceramics, or FRP is preferably adopted as the material of the molding die 12.

Furthermore, if not only the simple rectangular parallelepiped shown in FIG. 1 but also a conventionally known method such as a plurality of split molds is used as the molding die 12, for example, it fits into a human hand and is easy to handle. Complex 3 with grips etc. to improve
The wiping cleaning tool 10 having a dimensional shape can be easily manufactured.

The discharge hole 12b does not hinder foaming due to volume expansion of the wiping / cleaning tool 10, and the melamine foam raw material M that foams inside the mold 12 is discharged from the outside of the mold 12 through the discharge hole 12b. The size is set to be sufficiently small and to have a predetermined air permeability so as not to leak into, and specifically, it is set to φ10 mm or less, and preferably φ5 mm or less. Further, if necessary, a porous release paper, a ceramic filter, or the like that physically covers the discharge hole 12b while ensuring air permeability and that is easily peeled from the obtained wiping / cleaning tool 10 is also used. By adopting these, the discharge hole 12b can be set large.

As described above, the discharge hole 12b is for discharging the vaporized foaming aid, the foaming agent, the water generated as a by-product during foaming, and the vapor of formaldehyde to the outside. This is because, if the generated steam is not properly discharged from the mold 12, the pressure of the steam, that is, the existence of the steam itself greatly hinders the formation of a homogeneous three-dimensional network structure due to foaming. Therefore, the generated steam can be sufficiently discharged, in other words, the pressure inside the molding die 12 is maintained regardless of the amount of the generated steam.
The expansion pressure at the time of foaming should be below.

As a result of examining the above reasons, the molding die 1
It was confirmed that the discharge hole 12b having an opening of at least about 0.2% or more with respect to the total surface area of No. 2 was required. Further, if the opening area of the discharge hole 12b is too large, various gases serving as a driving force for foaming the melamine foam raw material M will also be discharged, and therefore it is necessary to set it so as not to hinder the foaming. The discharge hole 12b
The position where is provided is not so limited because the generated gas to be discharged has a high degree of freedom of movement, and the generated gas exits from the mold 12 as uniformly as possible, for example, only on the upper surface of the mold 12. There is no problem if they exist homogeneously.

[0029]

[Manufacturing Method] A manufacturing method of obtaining the wiping cleaning tool 10 from the melamine foam raw material M using the manufacturing apparatus 30 will be described with reference to FIGS. 3 and 4. Basically, the method for manufacturing the wiping cleaning tool 10 according to the present embodiment is a raw material preparation in which all the raw materials that are the bases of the wiping cleaning tool 10 to be manufactured in the raw material adjusting / kneading section 32 are prepared by mixing and kneading. Process S
1 and the amount of the melamine foam raw material M intentionally controlled by the pouring / foaming unit 40 is injected into the molding die 12 to foam /
Injection to obtain a wiping / cleaning tool 10 having an outer contour shape that matches the inner contour shape of the mold 12 by curing.
It includes a foaming step S2 and a final step S3 in which post-processing such as polishing into a predetermined shape and a predetermined inspection are performed on the obtained wiping / cleaning tool 10 (see FIG. 3).

The raw material preparing step S1 is a step of producing a raw material of the wiping cleaning tool 10 to be obtained. Specifically, melamine, which is the main raw material, is mixed with formaldehyde, and additives such as a foaming agent, a foaming auxiliary agent, an emulsifier, a surfactant, a pH adjuster, and a curing catalyst are mixed to form a melamine foam raw material M. Is a step of obtaining.

In place of the melamine and formaldehyde, a melamine-formaldehyde precondensate prepared in a separate step in advance may be used. The number average molecular weight of those preferably used as the precondensate is 200
It is about 1200, especially about 200 to 400. In this case, the time required for condensation can be shortened and the production efficiency can be improved. When preparing the melamine-formaldehyde precondensate, the molar ratio of melamine and formaldehyde is melamine: formaldehyde = 1: 1.5: 1:
A range of 4, especially 1: 2 to 1: 3.5 is preferred.

Further, as the monomer for suitably producing the melamine-formaldehyde precondensate, a part of the melamine and formaldehyde may be replaced with another monomer. Examples of the monomer corresponding to the melamine include alkyl-substituted melamine, urea, urethane, carboxylic acid amide, dicyandiamide, guanidine, sulfurylamide, sulfonic acid amide, aliphatic amine or phenol or a derivative thereof, etc. As the monomer, acetaldehyde, trimethylolacetaldehyde, acrolein, benzaldehyde,
Furfurol, glyoxal, phthalaldehyde, terephthalaldehyde and the like can be mentioned. By substituting these with other monomers, the effect of arbitrarily controlling the hardness of the wiping cleaning tool 10 to be obtained can be expected.

Examples of the foaming solvent added as the additive include pentane, trichlorofluoromethane, trichlorotrifluoroethane and the like. The curing catalyst is usually formic acid, and the emulsifier is anionic solvent such as sodium alkylsulfonate. An ionic surfactant or the like is used. Further, as described above, a pH adjusting agent is appropriately used which ensures the fluidity to such an extent that the reaction proceeds more than necessary until the injection into the mold 12 in the next step and the injection is not hindered.

The foaming / drying step S2 is performed as described above.
After the melamine foam raw material M obtained in the raw material preparation step S1 is intentionally injected into a required molding die 12 in a controlled amount, the molding die 12 is closed, and foam molding is performed under a volume restriction. This is a process of drying, and a mold injection step S2
1, a mold closing step S22, a foaming step S23, and a drying step S24 (see FIG. 3). The foaming / drying step S2
Each step S21 to S24 of FIG. 4 will be described step by step with reference to FIG. 4. First, the melamine foam raw material M is injected into the mold 12 in an open state (mold injection step S21: see FIG. 4 (a)). ). Then, the mold 12 in which the intentionally controlled amount of the melamine foam raw material M has been injected is closed (mold closing step S22: see FIG. 4B).

Then, the molding die 12 is closed.
Is transferred to a predetermined position by the transfer means 42 and the foaming step S23 and the drying step S24 are performed. In the case of this embodiment, the microwave irradiation device
Used as the drying means 44, the melamine foam raw material M is foamed by being heated by microwaves.
After the curing and the completion of the foaming / curing, the energy of the microwave irradiation is used to evaporate formaldehyde and water which are by-products generated at the time of foaming, that is, to dry the obtained wiping / cleaning tool 10 (FIG. 4 (c). )) (For details, see the related art [0005]).

In the foaming step S23, a mechanism for obtaining a uniform wiping / cleaning tool 10 from the melamine foam raw material M being foamed will be explained with reference to FIG. 5 as follows. Microwave irradiation heats a part of the melamine foam raw material M to start foaming (see FIG. 5 (a)). Foaming due to the generation of gas starts at the heated portion, and similar foaming also starts at other portions with a slight time difference. At this time, there is a difference in the degree of foaming described above due to a slight time shift in the start (see FIG. 5 (b)). Such foaming occurs in each part of the melamine foam raw material M, and the foaming progresses over time, so that the melamine foam raw material M being foamed spreads throughout the molding die 12 (Fig. 5 (c)).

When the foamed state reaches this state, expansion due to further foaming is restricted by the mold 12, that is, by volume (see FIG. 5 (d)). Under such a volume limitation, the expanding skeletons press each other, thereby reaching a shape equilibrium and stabilizing. Specifically, those of small size have not yet completed condensation / curing,
That is, it is taken in by a large one due to the movement of the movable constituent material of the skeleton (see FIG. 5 (e)). As a result,
Eventually, the skeleton reaches a geometrical equilibrium due to cell unification and stabilizes at a certain size, that is, becomes a homogeneous skeleton structure. In this state, condensation and curing of the skeleton are completed and the skeleton shape is fixed. Be converted.

In the present embodiment, for continuous production, the foaming / drying means 44 is constructed so as to be capable of heating the molding die 12 in the middle of the transfer path of the transfer means 42. The transfer means 42 may be stopped at the position where it reaches the foaming / drying means 44 for a time required for foaming / curing and drying.

Also regarding the foaming / drying means 44,
You may make it comprised for each function, ie, two for foaming and hardening, and for drying. In this case, it becomes possible to optimally set the energy required for foaming / curing or drying, respectively, and as a result, it is possible to reduce the manufacturing cost and to perform microwave irradiation capable of achieving uniform heating for foaming, For drying, the obtained wipe cleaning tool 1
Optimization by a suitable method with a hot stove below the softening point of 0 can be expected.

The microwave irradiation is preferably used because it can uniformly heat the entire melamine foam raw material M, that is, it can form a homogeneous foam structure. At that time, the microwave irradiation is preferable. The electric power consumption at that time is set within a range of 500 to 1200 kW, preferably 600 to 800 kW, for 1 kg of the raw material. This is because if the power consumption is too low, it will not foam sufficiently, and if it is too high, the pressure of the raw material during foaming will be very high, and the raw material may scatter and the shape cannot be retained or an explosion may occur. Is considered. Further, the foaming / drying means 4
As for 4, in addition to microwave irradiation, conventionally known appropriate means such as normal heating or irradiation with electron beam or high frequency can be adopted.

The final step S3 finally performed is a step of removing the obtained wiping / cleaning tool 10 from the inside of the mold 12, and performing post-processing such as polishing into a predetermined shape and predetermined inspection. Thus, the wiping / cleaning tool 10 as the final product is completed by going through this step S3.

In the present embodiment, the manufacturing apparatus 30 capable of continuously manufacturing the wiping / cleaning tool 10 by using a plurality of molding dies 12 is given as an example, but the present invention is not limited to this, and for example, Injecting and mixing the melamine foam raw material M
A so-called batch-type manufacturing apparatus in which each step such as kneading, foaming / drying, and post-processing is individually performed may be employed.

In the case of the conventional slab foaming method, since the foaming range is not limited in volume by using a molding die or the like, the melamine foam raw material M which is subjected to microwave irradiation foams up to its foaming limit.・ Since it has expanded, there is a large difference in density between the central part and the end part, and the density is 1 even at the part close to the central part.
It will be reduced to about 0 kg / m ³ . When the foaming proceeds to such a low density, the three-dimensional network structure skeleton of the wiping / cleaning tool 10 obtained by the microwave irradiation capable of performing the uniform foaming described above has a space between the central portion and its end portion. However, of course, it is empirically known that even the central portion becomes non-uniform. Therefore, in order to manufacture a melamine foam having a homogeneous three-dimensional network structure, the injection amount of the melamine foam raw material M into the molding die 12 is set at a density of the obtained wiping cleaning tool 10 of at least 10 kg / m ³ or more. It must be calculated in advance so that it can be foamed under restrictions.

This is a molding die 12 having a limited space below the volume in which the injected melamine foam raw material M can foam, and the foaming is geometrically suppressed before the foaming limit point is reached, that is, This is to avoid a structural (three-dimensional network structure) inhomogeneity in the wiping / cleaning tool 10 obtained by foaming under a volume limitation and to obtain a desired density.

On the other hand, the amount of the melamine foam raw material M injected into the mold 12 in the mold injection step S21 is determined by the density and volume of the wiping cleaning tool 10 to be obtained, that is, the volume of the mold 12. To be done. Since the density has a limit of at least 10 kg / m ³ or more, it can be said that the amount of the melamine foam raw material M to be injected is substantially determined only by the volume of the mold 12. When calculating the injection amount, water and formaldehyde, which are by-products, and other volatile components are discharged from the wiping / cleaning tool 10 from the melamine foam raw material M, so it is necessary to determine them in consideration of their values. There is.

[0046]

[Modification] In the above-described embodiment, one kind of melamine foam having the same physical properties such as density was used as the wiping / cleaning tool 10. However, like the wiping / cleaning tool 20 shown in FIG. Cleaning section 22 that uses tools and other physical properties,
For example, the grip portion 24 made of a commercially available melamine foam that is more flexible and easy to grip may be integrally configured.
In this case, the part to be cleaned, that is, the cleaning unit 2
Since the foam having the optimum physical properties can be adopted for the 2 and the grip portion 24 that is gripped at the time of cleaning, the wiping / cleaning tool 20 that is easy to hold and has excellent cleaning performance can be obtained.

The cleaning part 22 and the grip part 24 are integrated by applying a methylol melamine aqueous solution to each joint surface by impregnation and heating by microwave irradiation or the like. In addition to this, any conventionally known method can be adopted. It should be noted that the grip portion 24 is made of a material other than melamine resin, or a water-resistant adhesive or the like is used for joining the cleaning portion 22 and the grip portion 24, and a water-impermeable joint is formed between the cleaning portion 22 and the grip portion 24. When a layer is formed,
When the wiping cleaning tool 20 is used, the cleaning section 22 and the grip section 2
It is considered that peeling of No. 4 may occur, or the water retention may be deteriorated due to a decrease in water permeability, resulting in deterioration of detergency. Therefore, caution is required.

As the grip portion 24, a commercially available conventional product may be adopted as described above, but melamine foam which constitutes the wiping and cleaning tool according to the present invention is adopted. For example, one side has a bending elastic modulus. It has high and good scraping ability, and the other has a low bending elastic modulus and greatly reduces the possibility of scratches, etc., so that it can be suitably used for automobile painting, tires and interiors, respectively. Good as a ingredient.

In addition to this, in the case of the wiping cleaning tool according to the present invention,
Since it is foamed by molding under volume limitation and its skeletal structure is homogenized as described above, the required coloring material is added in advance to the raw material of the wiping / cleaning tool to achieve the required coloring. In addition, it is possible to provide a wiping / cleaning tool with improved product power without color unevenness.

[0050]

[Experimental Example] An experimental example of the melamine foam obtained by using the molding die according to the embodiment and the discharge hole formed in the molding die when the melamine foam is obtained by so-called molding is shown below. The melamine foam and the manufacturing method thereof according to the present invention are not limited to this experimental example.

(Experiment 1) Relationship between the discharge hole of the mold and the obtained wiping / cleaning tool Methylol melamine obtained by precondensing formaldehyde with respect to melamine which is a main raw material, a foaming agent, a foaming auxiliary agent,
A melamine foam raw material was prepared by mixing a surfactant and an additive such as a curing catalyst.
(0 kg / m ³ ), and after stirring with a stirrer at a rotation speed of 3000 rpm for 45 seconds to homogenize the raw material, a predetermined discharge hole with dimensions of 160 mm × 110 mm × 20 mm (volume 352000 mm ³ ). Was injected into a mold provided with a microwave oven, and microwave irradiation was performed under the conditions of an output of 1 kW and 140 sec. Then, the obtained melamine foam was demolded and dried at 150 ° C. for 4 hours to obtain a density of 30 kg / m ^3. The test bodies according to Examples 1 to 3 and Comparative Examples 1 to 5 were obtained. Then, for each of the obtained test specimens, the appearance state, the skeleton (foaming) state and the cell diameter are visually observed, and the appearance state is ◯ ××,
The skeleton (foaming) state was evaluated as homogeneous to heterogeneous. The perforation pattern of the ejection holes perforated in the used mold and the total area thereof are shown in Table 1 below. The discharge holes are made of porous release paper so that the melamine foam raw material during foaming does not leak out.

The additives used and the amounts thereof mixed are as follows. Foaming agent: tap water (15 parts by weight based on 100 parts by weight of methylol melamine) Blowing aid: trade name HFE-7100; Sumitomo 3M (5.1 parts by weight based on 100 parts by weight of methylol melamine) Activator: trade name Ripon LS-250; manufactured by Lion (40 parts by weight based on 100 parts by weight of methylol melamine) -Curing catalyst: trade name formic acid (87%); manufactured by Mitsubishi Gas Chemical (based on 100 parts by weight of methylol melamine) 5.4 parts by weight)

[0053]

[Table 1]

(Results of Experiment 1) The results obtained are also shown in Table 1 above. For reference, data on a commercially available melamine foam produced by slab foaming is also shown.
Based on the obtained results, the discharge surface was used as a discharge hole of 0.
It was confirmed that if the opening of about 2% or more is secured, a good wiping / cleaning tool can be obtained regardless of the opening portion. Also, the cell diameter was smaller (about 1/4) than that of the conventional slab foamed product. It is considered that this is because uniform foaming is performed.

(Experiment 2) Physical Properties of Molding, that is, Wiping Cleaning Tool Obtained by Molding as Hard Foamed Plastic Using the molding die of Example 1 for which good results were obtained in Experiment 1 described above, Using the same melamine foam raw material and conditions as described in 1, the injection amount (density of the obtained wiping cleaning tool) was 12 g (20%) as shown in Table 2 below.
kg / m ³ ), 18 g (30 kg / m ³ ), 24 g (40 kg /
m ³ ), 30 g (50 kg / m ³ ), 42 g (70 kg / m ³ ),
72g (120kg / m ³ ) and 84g (140kg / m ³ )
Examples 4 to 9 (density 30 kg / m ³
As a result, the test sample of the wiping cleaning tool according to Example 1 according to Experiment 1 will also be described. Then, for each of the obtained test pieces, the appearance state, the washability, and the bending strength (MP
A), flexural modulus (MPa) and compressive strength (kPa) were observed and measured. Appearance and detergency were evaluated visually or by sensory with ○ to ×, and bending strength (MP
JIS K 7 for a) and flexural modulus (MPa)
221 “Bending test method for rigid foamed plastics” is specified by JIS K 7 for compressive strength (kPa).
The measurement was carried out by the method specified in "Compression Test Method for Rigid Foamed Plastic" of No. 220. The term "cleanability" as used herein refers to the degree of removal of stains when the area around a car or kitchen that is intentionally soiled is wiped up using each test body.

[0056]

[Table 2]

(Results of Experiment 2) The results obtained are also shown in Table 2 above. From this result, when the density is 20 kg / m ³ , there is no flesh in the appearance and the product is durable enough to be used as a product, but the cleaning property is poor and sticky dirt can be removed sufficiently. There wasn't. Also, the bending strength is not sufficient at 0.1 MPa, and there is a concern that cracking may occur during continuous use. Density is 30 kg /
It was confirmed that when m ³ or more, both the cleaning property and the bending strength are sufficient. The density is 140k
In the case of g / m ^3, the flexural modulus having a positive correlation with the hardness exceeds 50 MPa. Therefore, if the density is higher than this, scratches are not formed during cleaning such as automobile coating. To be a problem. The compressive strength, which represents the shape retention, is a sufficient value at the stage of 30 kg / m ³ ,
Even at 20 kg / m ^3, it was durable to use.

(Experiment 3) Relationship between mixing amount of surfactant and chemical detergency (density is 50 kg / m ^{3 in} all) The molding die of Example 1 for which good results were obtained in Experiment 1 was used. Examples 10 to 12 were used, with the same melamine foam raw materials and conditions as described in Experiment 1 and with different composition of surfactants shown in Table 3 below.
(The density of 50 kg / m ³ is also shown in Example 6 of Experiment 2.) Alignment Comparative Examples 6 to 8 were used to obtain test pieces of the cleaning tool. And the skeleton (foaming) of each obtained test body
The condition, cleaning property, and bending strength (MPa) were observed and measured. The skeleton (foaming) state is homogeneous to heterogeneous, the washability is evaluated by visual or sensory with ◯ to ×, and the bending strength (MPa) is determined according to JIS K 7221.
“Bending test method for rigid foamed plastic” of 1.

[0059]

[Table 3]

(Results of Experiment 3) The results obtained are also shown in Table 3 above. From these results, from the viewpoint of skeleton (foaming) state, detergency and bending strength, at least the melamine resin 10
It has been confirmed that it is sufficient if 20 parts by weight, preferably 40 parts by weight, of the surfactant are mixed with 0 part by weight. If the amount exceeds 100 parts by weight, the bending strength will be 0.1.
It decreases to around MPa.

[0061]

As described above, according to the wiping cleaning tool and the method of manufacturing the same according to the present invention, the melamine foam raw material is injected into the required molding die in an intentionally controlled amount so as to be limited. Since the wiping / cleaning tool is produced by foaming in a space under a limited volume, it has a uniform three-dimensional network skeleton, and has a desired density such as handleability and bending strength when the wiping / cleaning tool is used. The mechanical strength of the rigid foamed plastic can be improved. Also, a melamine foam having a complicated three-dimensional shape can be easily manufactured. Further, with the slab foaming, it is possible to avoid the deterioration of the yield due to the end cut or the like, which cannot be avoided in manufacturing.

[Brief description of drawings]

FIG. 1 is a perspective view showing a wiping and cleaning device according to a preferred embodiment of the present invention.

FIG. 2 is a schematic view showing an example of a manufacturing apparatus for manufacturing the wiping / cleaning tool according to the embodiment by molding.

FIG. 3 is a flowchart showing a method for manufacturing a wiping cleaning tool according to an embodiment.

FIG. 4 is a process drawing showing a foaming / drying process S2 related to the method for manufacturing the wiping cleaning tool according to the embodiment.

FIG. 5 is an explanatory view for stepwise explaining homogenization of the skeletal structure at the time of foaming of the melamine foam constituting the wiping cleaning tool.

FIG. 6 is a perspective view showing a wiping and cleaning tool according to a modification.

FIG. 7 is an explanatory diagram for explaining stepwise a change in the skeletal structure of a melamine foam that constitutes a wiping cleaning tool in foaming a slab during foaming.

[Explanation of symbols]

10 Melamine foam 12 Mold M Melamine foam raw material

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideo Suzuki             Stock No.5, 380, Horiyamashita, Hadano City, Kanagawa Prefecture             Inoac Technical Research Institute (72) Inventor Souko Nakajo             Stock No.5, 380, Horiyamashita, Hadano City, Kanagawa Prefecture             Inoac Technical Research Institute (72) Inventor, Ohta bile             Aichi Prefecture Anjo City Imaikecho 3 1-336 Stock             Inoac Corporation Anjo Business             In-house F-term (reference) 3B074 AA02 AA03 AB02                 4F204 AA38 AB02 AG20 AH51 AH53                       AH71 AR15 AR20 EA01 EA04                       EB01 EE16 EK18 EL15

Claims (5)

[Claims] 1. An internal contour of the mold (12) by intentionally injecting a controlled amount of a melamine foam raw material (M) into a required mold (12) and foaming it under volume limitation. It has an external contour that matches the shape and is composed of a three-dimensional network skeleton of homogeneous melamine resin, its density is set to ³⁰ to 140 kg / m ³ , and bending strength is set to at least 0.1 MPa or more. A wipe cleaning tool characterized in that. 2. The wipe cleaning tool according to claim 1, wherein 20 to 100 parts by weight of a surfactant is mixed with 100 parts by weight of the melamine foam raw material (M). 3. A melamine foam raw material (M) is poured into a required molding die (12) and foamed under a volume restriction, so that an outer contour matching the inner contour shape of the molding die (12). A foamed molded product having a shape is obtained, and by controlling the amount of the melamine foam raw material (M) injected into the molding die (12) at this time, the density of the resulting foamed molded product is 30 to 30%. A method for manufacturing a wiping cleaning tool, characterized in that the bending strength is set to 140 kg / m ³ and the bending strength is set to at least 0.1 MPa or more. 4. The method of manufacturing a wiping / cleaning tool according to claim 3, wherein the mold (12) has a discharge hole (12b) for discharging various gases generated during foam molding. 5. The method for manufacturing a wiping cleaning tool according to claim 3, wherein an opening area of the discharge hole (12b) is set to be at least 0.2% or more of a total surface area of the molding die (12).