JP2001335691A - Resin composition for molding and molded article using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for molding capable of obtaining a molded article having excellent anti-fouling property at a low cost, and to provide a molded article using the composition. SOLUTION: This resin composition contains a low molecular weight silicone resin having molecular weight of 1,000 to 50,000, a high molecular weight silicone resin having molecular weight of 200,000 to a million, and a higher fatty acid amide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding resin composition capable of obtaining a molded article in which dirt hardly remains, and a molded article using the same.

[0002]

2. Description of the Related Art In recent years, resin-molded articles have been widely used in water-related areas such as washrooms, kitchens, and bathrooms. To be more specific, toiletries include soap dishes, washbasins, dust boxes, etc., and kitchenware include colanders, bowls, kitchen pockets, trays, sink corners, cooking bats, tawasilacks, wash tubs, sink mats, drainers Cases and the like can be mentioned, and examples of bath products include a shampoo stand, a dust box, a hot tub, a bath chair, and a hand tub. Examples of other resin molded articles include a washing tub and a dehydration tub of a washing machine, a nursing toilet, a food transport container, a bucket, and the like.

[0003] These resin molded articles are generally useful in that they have water repellency and do not deteriorate with chemicals such as neutral detergents. There is a problem that it is difficult to remove. Therefore, these resin molded products are given a shape that is easy to wash and clean, or the surface of the molded product is made mirror-finished by using a mold with a mirror-finished surface, so that the surface is hardly stained. Has been made.

[0004]

However, these resin molded products are often handled in a state of being overlapped with each other at the time of distribution or stock keeping, so that the overlapping portion is often damaged and stained therefrom. In addition, since many resin molded products have a long service life of 3 to 5 years, the surface is damaged during that time, so that they are easily stained. Furthermore, even though they are used every day, those that are not cleaned or cleaned, or those that are difficult to clean or clean due to their shape, have a great deal of dirt attached and deposited even if the surface is mirror-finished. The dirt once adhered cannot be easily removed.

[0005] For example, bathware (especially a bathtub, bath chair, tub, etc.) adheres and accumulates scales mixed with human dirt and soapy water, and kitchenware (especially trays, sink corners, cooking vats, etc.). Oil stains such as food waste, cooking oil, seasoning oil, etc. adhere and accumulate on the trash box. In addition, human scales, scales, and the like adhere and accumulate in the washing tub and the dehydration tub of the washing machine.

Therefore, in order to impart a function (antifouling property) to the molded article itself, which can be easily wiped off even if dirt adheres and the dirt is hardly left, the molding material has a high molecular weight of several million. It has been proposed to incorporate a silicone resin having a molecular weight, and some have been put to practical use. However, since the high-molecular-weight silicone resin has a high viscosity, it cannot be kneaded without using a large-scale kneader such as a three-roll mixer when mixing with a main component resin such as polypropylene, and the equipment cost is high. There is a problem of sticking.

The present invention has been made in view of such circumstances, and provides a molding resin composition capable of inexpensively obtaining a molded article having excellent antifouling properties, and a molded article using the same. For that purpose.

[0008]

In order to achieve the above object, the present invention provides a low molecular weight silicone resin having a molecular weight of 1,000 to 50,000, a high molecular weight silicone resin having a molecular weight of 200,000 to 1,000,000, and a higher fatty acid amide. The first aspect of the present invention is a molding resin composition containing, in particular, the low-molecular-weight silicone resin is 0.02 to 5% by weight, the high-molecular-weight silicone resin is 0.02 to 5% by weight, A second aspect is a molding resin composition containing 0.006 to 0.3% by weight of a higher fatty acid amide. Further, among these, the third gist is that the higher fatty acid amide is oleic acid amide.

According to the present invention, a molded article obtained by using any of the molding resin compositions according to the first to third aspects is a fourth aspect.

[0010]

Next, an embodiment of the present invention will be described.

The molding resin composition of the present invention contains a low molecular weight silicone resin, a high molecular weight silicone resin and a higher fatty acid amide in the resin composition.

First, as a resin which is a base of the resin composition for molding, any resin conventionally used as a molding material for a resin molded article may be used, for example, low density polyethylene, high density polyethylene, polypropylene and the like. And various polyolefin-based resins.

[0013] The low molecular weight silicone resin contained in the base resin is a silicone resin having a molecular weight of 1,000 to 50,000, and among them, a resin having a molecular weight of 10,000 to 40,000 is preferable. The low-molecular-weight silicone resin functions to exude from the inside of the molded article to the surface of the molded article with time and exhibit the antifouling property for a long time.

The low-molecular-weight silicone resin is preferably contained in an amount of 0.02 to 5% by weight (hereinafter abbreviated as "%") based on the whole composition. That is, if it is less than 0.02%, even when used in combination with a high molecular weight silicone resin, it is difficult to obtain excellent antifouling properties. Conversely, if it exceeds 5%, problems in operability during molding are likely to occur. .

The high-molecular-weight silicone resin used together with the low-molecular-weight silicone resin is defined as having a molecular weight of 20 or less.
A silicone resin having a molecular weight of 300,000 to 500,000 is preferable. The high molecular weight silicone resin has a function of being partially exposed to the surface of the molded product from the beginning and exhibiting antifouling properties at that portion.

The high molecular weight silicone resin is preferably contained in an amount of 0.02 to 5% based on the whole composition. That is, if it is less than 0.02%, even when used in combination with a low molecular weight silicone resin, it is difficult to obtain excellent antifouling properties. Conversely, if it exceeds 5%, it is easy to mix uniformly with other resin components. This is because the manufacturing cost increases.

[0017] Examples of the type of these silicone resins include organopolysiloxane, dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane and the like. Among them, dimethylpolysiloxane is preferably used.

Further, the higher fatty acid amide used together with these resin components imparts slidability and abrasion resistance to the molded product, and together with the presence of the above two types of silicone resins, It fulfills the function of expressing better antifouling properties. Such higher fatty acid amides include saturated fatty acid amides, unsaturated fatty acid amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, and the like, and the saturated fatty acid amides include stearic acid amide and behenic acid amide, Examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Examples of the saturated fatty acid bisamide include ethylene bisstearic acid amide and the like. Examples of the unsaturated fatty acid bisamide include ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N'-
And dioleyl sebacamide. These may be used alone or in combination of two or more. Of these, it is preferable to use oleic acid amide, which is an unsaturated fatty acid amide.

The higher fatty acid amide is preferably contained in an amount of 0.006 to 0.3% based on the whole composition. That is, if it is less than 0.006%, the effect of improving the antifouling property of the molded article is small, and if it exceeds 0.3%,
This is because the higher fatty acid amide may bleed from the surface of the molded article, making it difficult to perform printing and the like.

In addition to the above components, the molding resin composition of the present invention may further contain, if necessary, a stabilizer, an antioxidant, an ultraviolet absorber, a pigment, a flame retardant, an antibacterial agent. , A processing aid and the like can be appropriately compounded.

The molding resin composition of the present invention is prepared by introducing the above-mentioned components into a suitable mixing and kneading machine such as a Banbury mixer, a kneader and a twin-screw kneading machine at a predetermined ratio, followed by melt-mixing and granulation. It can be obtained as a granular composition. At this time,
Since the high-molecular-weight silicone resin is melted by the compatibility with the low-molecular-weight silicone resin and the higher fatty acid amide, the components such as a gear pump can be sufficiently used without using a large mixer such as a three-roll mixer as in the past. It can be mixed and granulated.

Instead of simultaneously mixing the above components, a masterbatch containing a silicone resin at a high concentration in a base resin and a masterbatch containing a higher fatty acid at a high concentration in a base resin are prepared. Alternatively, the desired resin composition for molding can also be obtained by further mixing the two components with other components that complement the components. That is, if a silicone resin and a higher fatty acid are simultaneously added to and mixed with the resin, mixing unevenness and slip may occur and processability may be deteriorated. To avoid this, separate master batches are used as described above. It is preferable to make However, in this case, the cost of the masterbatch of the high-molecular-weight silicone resin is high. Therefore, it is necessary to suppress the cost increase by reducing the content of the masterbatch.

Using the resin composition for molding, various molded articles can be obtained by ordinary molding methods such as injection molding and extrusion molding. The molded article thus obtained has excellent antifouling properties, and the antifouling properties are not impaired for a long time. Therefore, it can be suitably used for a wash surface molded product, a kitchen molded product, a bath molded product, a sanitary molded product, a home appliance molded product, and the like, in which dirt has conventionally been a problem. In addition, since the equipment cost is lower than that using only a high molecular weight silicone resin, there is an advantage that a molded product can be provided at a low price.

Next, examples will be described together with comparative examples.

[0025]

Examples 1 to 11 and Comparative Examples 1 to 8 A polypropylene resin was used as the base resin, and a low molecular weight silicone resin having a molecular weight of 40,000 (viscosity of 3000 centistokes, 25
C.) and a high molecular weight silicone resin having a molecular weight of 300,000 (viscosity of 8 million centistokes, 25 ° C.). Oleic acid amide was used as the higher fatty acid. However, the low molecular weight silicone resin was blended after preparing a master batch containing 12% of the polypropylene resin with respect to the polypropylene resin. Also, high-molecular-weight silicone resin is used in combination with polypropylene resin.
A master batch containing 0% was prepared and then blended.
Furthermore, higher fatty acids were also blended after preparing a masterbatch containing 3% of this with respect to the polypropylene resin. As shown in Tables 1 to 4 below, these are melt-mixed at an appropriate ratio (in each table, the unit of the composition is%), and a 5 cm × 5 cm × 2 mm-thick plate-like test piece is formed by an injection molding machine. Produced. Then, the initial antifouling property and the antifouling property after repeated washing were evaluated by the following methods.
In addition, the workability in uniformly mixing the raw materials for producing a master batch was also evaluated. The results are shown in Tables 1 to 4 below.

[Initial antifouling evaluation method] Since "oil" is a typical substance which adheres to the surface of a synthetic resin molded article and does not easily remove dirt, the contaminant containing "oil" is as follows.
Oil-based ink A was used. Then, the oil-based ink A is
Approximately 0.3 milliliter was dropped on the surface of the test piece from above at a height of 3 cm, and the diameter of the circle in a state of being spread in a circular shape was measured. The smaller the diameter is, the more repellent the soil is, and it can be evaluated that the antifouling property is excellent. In addition, the stains were left for 72 hours, and then repeatedly wiped with a wet tissue (Wakodo Co., Ltd., towel wetty) while applying a constant load, thereby counting the number of times the stains could be completely wiped off. It can be evaluated that the smaller the number is, the more excellent the antifouling property is.

[Method of Evaluating Antifouling Property after Repeated Washing] The test piece was stained with oil-based ink A in the same manner as described above, and was washed off with a detergent 50 times and 100 times. The diameter of the dirt circle of the oil-based ink A and the number of times of wiping were examined. This makes it possible to evaluate whether the initial antifouling property is maintained over time. In order to prevent a difference in the surface condition of the molded product from being caused by a difference in the number of times of wiping, the wiping operation was always repeated 20 times, regardless of the number of times the dirt was wiped off.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

[Table 4]

From the above results, it can be seen that all of the products of Examples 1 to 9 have excellent antifouling properties, and that the antifouling properties are maintained for a long period of time. On the other hand, it can be seen that all of Comparative Examples 1 to 6 are inferior in antifouling property to the Examples. The product of Comparative Example 3 had no problem in antifouling properties, but was expensive because it used only a high molecular weight silicone resin.

As a whole, the antifouling property tends to be improved when the number of times of washing is increased as compared with the initial molded article. This is because the surface of the initial molded article has a release agent. This is considered to be because it adheres to the oil-based ink A and is difficult to wipe off. Therefore, in order to confirm how many times washing is repeated, excellent antifouling property is expressed,
The product of Example 1 was again subjected to an antifouling property evaluation test in which the number of times of wiping was counted while changing the number of times of washing. The results are shown in Table 5 below.

[0034]

[Table 5]

From the above results, it was found that the influence of the release agent or the like on the surface of the molded product can be eliminated immediately by repeating the washing several times, and thereafter, excellent antifouling properties are exhibited. Was.

In order to confirm whether the same effect can be obtained by using different types of oil-based inks,
For the product of Example 1 and the products of Comparative Examples 1 to 6, using an oil ink B different from the oil ink A as a contaminant,
Initially, antifouling properties were evaluated in the same manner as described above.
The results are shown in Table 6 below.

[0037]

[Table 6]

From the above results, it can be seen that the product of Example 1 also has an excellent antifouling property with respect to the oil-based ink B as compared with the products of Comparative Examples 1, 2, and 4 to 6. As described above, the product of Comparative Example 3 has no problem in antifouling properties, but has a problem that it is expensive because it uses only a high molecular weight silicone resin.

Further, since "bath articles" can be considered as one of the uses of the molded article of the present invention, a hydrophobic stain substance (carbon black of 20 to 130 nm) is used in consideration of stains adhering to the bath articles. An artificial soil C dispersed and contained in a hydrophilic solution (ethanol) (assuming a soil in which a hydrophobic soil such as oil or grime adheres in a mixed state with moisture, etc.) and a hydrophilic soil substance (powder-like α-iron oxide) ) Is dispersed and contained in a hydrophilic solution (ethanol), artificial stain D (assuming hydrophilic stain such as sweat)
Was used to evaluate the antifouling property in the same manner as described above. In addition, ethanol was used as the hydrophilic solution in order to uniformly disperse carbon black and α-iron oxide without secondary aggregation in the solution.

The composition of the artificial soil C is 0.2% for carbon black and 99.8% for ethanol.
The composition of the artificial soil D is α-iron oxide: 0.2
%, Ethanol: 99.8%. Then, as examples, two kinds of examples 10 and 11 having different compositions from the above examples 1, 2, and 4 were prepared. Further, as comparative example samples, comparative examples 1 and 4 to 6 and new two kinds of comparative examples 7 and 8 having different compositions were prepared. The results are shown in Tables 7 to 9 below together with the composition of each sample.

[0041]

[Table 7]

[0042]

[Table 8]

[0043]

[Table 9]

From the above results, it can be seen that all of the products of the examples show excellent antifouling properties against both artificial stains C and D as compared with the products of the comparative examples. The product of Example 11 containing a large amount (0.5%) of a high molecular weight silicone resin has particularly excellent antifouling properties.

[0045]

As described above, since the molding resin composition of the present invention contains a low molecular weight silicone resin, a high molecular weight silicone resin, and a higher fatty acid amide, it can be mixed with a simple mixer such as a gear pump. These can be uniformly mixed, and the equipment cost can be reduced. The molded product obtained using the molding resin composition is not only inexpensive, but also in combination with the characteristics of the above three, and exhibits excellent antifouling properties over a long period of time. Can be applied to various molded articles required to maintain the following.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masaya Ishida 1-4-1-19 Minamimori-cho, Kita-ku, Osaka-shi, Osaka Kanebo Kasei Co., Ltd. BB001 BB031 BB121 CP032 EP016 EP026 GC00 GG00

Claims (4)

[Claims] 1. A molding resin composition comprising a low molecular weight silicone resin having a molecular weight of 1,000 to 50,000, a high molecular weight silicone resin having a molecular weight of 200,000 to 1,000,000, and a higher fatty acid amide. 2. The method according to claim 1, wherein the low molecular weight silicone resin is 0.02 or less.
~ 5 wt%, the high molecular weight silicone resin is 0.02-
2. The molding resin composition according to claim 1, which contains 5% by weight and 0.006 to 0.3% by weight of a higher fatty acid amide. 3. The molding resin composition according to claim 1, wherein the higher fatty acid amide is oleic acid amide. 4. A molded article obtained by using the molding resin composition according to any one of claims 1 to 3.