JPH03215567A - Synthetic resin molding and impartation of persistence of antifogging property thereto - Google Patents

Abstract

PURPOSE:To obtain a synthetic resin molding with excellent persistence of antifogging properties by adding a nonionic nitrogen-free antifogging agent and an additive selected from among specified organic compounds to at least one surface of the molding. CONSTITUTION:A synthetic resin molding is obtained by adding a mixed additive comprising 5-200mg/m<2> of a nonionic nitrogen-free antifogging agent (e.g. desirably glycerol higher fatty acid ester with an HLB of 3-12) and 1-100mg/m<2> of at least one additive selected from among a polyoxyethylenealkylamine of formula I, a polyoxyethylenealkylamide, a polyoxyethylenealkylamine fatty acid ester of formula II and a polyoxyalkylenealkylamide fatty acid ester to at least one surface of the molding. This molding can retain its antifogging properties for a very long time and can preserve food for a long time when used as a packaging material.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a synthetic resin molded product with excellent anti-fogging properties and prevents the growth of mold, fungi, etc., and imparts anti-fog properties to synthetic resin molded products. It is about the method.

[Prior Art] Synthetic resins are widely used as films, sheets, wall materials, ceiling materials, and other molded products. In particular, films and sheets are used in the form of wrapping films, bags, containers, etc., and are used for packaging various articles. is being carried out. Since many synthetic resins are hydrophobic and water droplets adhere to their surfaces in humid environments, it is common practice to prevent water droplets from adhering to the surface of the molded product by adding various surfactants to the surface. It is being said.

For example, Japanese Patent Publication No. 3g-4174 describes the use of monoglycerides of fatty acids to prevent water from accumulating on the surface of polyolefin films and dew from forming on the surface of polyolefin films.
Japanese Patent Publication No. 3-8605 discloses the use of a fatty acid ester of polyglycerin for the same purpose, and Japanese Patent Publication No. 38-3572 discloses the use of a fatty acid ester of sorbitan for the same purpose. Although these exhibit some degree of anti-fogging properties under limited conditions and for a relatively short period of time, they are by no means sufficient under severe conditions and when long-term durability is required.

In addition, in films used for agricultural greenhouses, etc., in order to improve anti-fogging durability, glycerin esters with a high degree of esterification are used as anti-fogging agents, or fatty acid esters of special polyhydric alcohols are used as anti-fogging agents. Pentaerythritol fatty acid ester (Special Publication No. 42-4271
There have been attempts to use fatty acid esters of 1-limethylolpropane (Japanese Patent Publication No. 43-880fi) in combination with glycerin fatty acid esters, but when these less hydrophilic substances are used in combination, the level of antifogging properties is rather low. This is undesirable because there may be cases where the performance decreases or the sustainability is hardly improved.

On the other hand, an attempt is made to improve the antistatic properties at low temperatures by using polyoxyethylene alkylamines, which have long been known as antistatic agents, and polyhydric alcohol fatty acid esters, etc. (Japanese Patent Publication No. 63-65098) ), those attempting to improve antifogging properties in a relatively short period of time by using diethanolalkylamines or diethanolalkylamides in combination with polyhydric alcohol fatty acid esters, etc. (Japanese Unexamined Patent Publication No. 53-31749), polyoxyethylene alkyl There are attempts to improve the sustained anti-fogging properties of films for vinyl greenhouses by using amines etc. in combination with polyhydric alcohol fatty acid esters (Japanese Patent Laid-Open No. 48-69845), but these efforts mainly focus on surface properties. It is used in combination to control dirt and stickiness, etc.
It is not intended to prevent the growth of mold or fungi.

However, there is no product that maintains a high level of anti-fog properties for a long period of time under any conditions, especially in environments where mold or mildew grows on the surface of synthetic resin products, such as under high temperature and humidity. There was nothing that could be maintained and used.

[Problems to be Solved by the Invention] The purpose of the present invention is to improve the above-mentioned drawbacks and provide an anti-fogging synthetic resin molded product that has excellent anti-fog durability under any conditions, and a synthetic resin molded product that prevents mold, fungi, etc. It is an object of the present invention to provide a method for imparting antifogging durability to an antifogging resin molded article by preventing growth on the product surface.

[Means and effects for solving the problem] The present inventor has worked diligently to develop a synthetic resin molded product that maintains anti-fog properties for a long period of time under any environmental conditions, and to find a method for maintaining anti-fog properties over a long period of time. As a result of repeated studies, the present invention has been completed. That is, (1) 5 to 200 mg/m2 of a nitrogen-free nonionic antifogging agent (A) on at least one surface of the synthetic resin molded product.
and polyoxyethylene alkylamine, polyoxyethylene alkylamide, -MQ formula I1 represented by the general formula ■
At least one additive selected from polyoxyethylene alkylamine fatty acid ester and polyoxyethylene alkylamide fatty acid ester represented by (B) 1 to 1
Synthetic resin molded product having a mixed additive consisting of 00mg/m2, provided that R is a 68 to C22 alkyl group, an alganyl group,
or an acyl group having the same group.

R' is selected from CI to G22 alkyl groups and alganyl groups.

n is O~10, m is 1~1O (2) Nonionic antifogging agent (A) that does not contain nitrogen 5~20
0 mg/m2, and at least one selected from polyoxyethylene alkylamine represented by the general formula (■), polyoxyethylene alkyl amide, polyoxyethylene alkyl amine fatty acid ester represented by the general formula II, and polyoxyethylene alkyl amide fatty acid ester A method for imparting anti-fogging properties to a synthetic resin molded product by making each of 1 to 100 mg/m2 of one type of additive (B) exist on the surface of the synthetic resin molded product - 1 and H2 and 21Jλ,H
``'' LC82G [20J, COR provided that R is selected from a C8 to C22 alkyl group, an alganyl group, or an acyl group having the same group.

R' is selected from 01-022 alkyl groups and alkenyl groups.

n is 0 to 10, m is 1 to 10 It provides:

As the synthetic resin of the present invention, both thermosetting and thermoplastic resins can be used, but preferably thermoplastic synthetic resins are used, such as polyolefin resins, plasticized vinyl chloride resins, vinylidene copolymer resins, and styrene resins. , boryamide resin, acrylic resin, polyester resin, etc.
Among these, preferred are styrene-butadiene block copolymers, polyester resins, polyolefin resins,
For example, high pressure low density polyethylene: density 0910~0
．． 935g/cm3, linear low density polyethylene (L
L): Density 0.910 to 0.935g/cm3, Linear very low density polyethylene (VL); Density 0.88
~0.91g/c+++3 ethylene vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer; density 0. 86 ~0. 88 g/cm" Ethylenically unsaturated fatty acids or their ester copolymers, ionomer resins, brobylene monopolymers and copolymers with other monomers, crystalline 1,2-bolybutadiene, etc., and more preferably << high pressure Legal low density polyethylene, LL, VL, EV
A etc.

In addition, the nitrogen-free nonionic antifogging agent (A) [hereinafter referred to as antifogging agent (A)] in the present invention includes, for example:
Glycerin higher fatty acid monoester. Polyhydric alcohol higher fatty acid esters such as sorbitan higher fatty acid monoester, polyglycerol higher fatty acid mono- or diester, sucrose higher fatty acid ester, polyoxyethylene alkyl ethers such as polyoxyethylene dialkyl ether, polyoxyethylene alkylphenyl ether,
Polyhydric alcohol higher fatty acid esters added with polyoxyethylene such as polyoxyethylene glycerin higher fatty acid ester and polyoxyethylene sorbitan higher fatty acid ester, preferably those with HLB = 3 to 12,
Those with LB=4 to 10 are more preferable. Among these, glycerin higher fatty acid esters are more preferred in terms of heat resistance and the like.

On the other hand, the additive (B) in the present invention may be one produced by a known method of reacting coconut amine or coconut amide derived from coconut oil with a desired number of ethylene oxide units, or one produced by a known method of reacting coconut amine or coconut amide derived from coconut oil with Those produced by known methods such as reacting beef tallow amine or tallow amide with a desired number of ethylene oxide units, or esters produced by reacting these with higher fatty acids can be used. For example, a single amine or single amide such as laurylamine, lauric acid amide, myristylamine, myristic acid amide, palmitylamine, palmitic acid amide, stearylamine, stearic acid amide, oleylamine, oleic acid amide, etc. can be added to a desired number of ethylene Additives (B
) can be used as R in additive CB)
has 8 to 22 carbon atoms, and R' has 1 to 22 carbon atoms.

If the number of carbon atoms in R is less than 8, it increases water solubility and impairs the sustainability of antifogging. If the number of carbon atoms in R or R' exceeds 22, the effect is small and it is difficult to put it into practical use from a raw material standpoint. . Moreover, n is O-10, and m is 1-10.

Those in which n and m each exceed 10 are also undesirable because they increase water solubility and impair the sustainability of antifogging.

Additives can be made to exist on the surface of synthetic resin by kneading them in advance and molding them, and then allowing them to bleed onto the surface of the molded product, or by diluting the additives with an appropriate organic solvent in advance and adding them to the synthetic resin molded product. Known methods such as coating or spraying on the surface can be used.

It is desirable to adjust the concentration of the additive present on the surface as appropriate depending on the type of packaged item, the required duration of fogging, the usage temperature conditions, etc., but for antifogging agent (A),
~200mg/m2, preferably 10-100mg
/m2, and 1 to 100 mg for additive (B)
/m2, preferably 2 to 60a+g/m2. Below the above values, there is almost no effect, and above the above values, the effectiveness reaches a plateau, and the surface becomes sticky.
Otherwise, it becomes dirty and causes serious surface contamination, which is undesirable.

Also, the preferred blending ratio of the antifogging agent (A) and the additive (B) is (A)/(B) = 1/2 = 05 to 1 70.05
= 20, and if it is less than 0.5, the antifogging properties will be somewhat inferior, while if it exceeds 20, the durability of the antifogging properties will be somewhat inferior, which is not preferable.

In addition, in the case of the method of kneading into the synthetic resin in advance, obtaining the above surface concentration may vary somewhat depending on the type of resin, the effective thickness of the resin layer, the time until the start of use, the storage environment temperature, etc. However, the antifogging agent (A) is preferably added at a concentration of 0.1 to 5.0% by weight in the synthetic resin.
, more preferably 0.2 to 4.0% by weight, and for additive (B), preferably 0.1 to 1.5% by weight,
More preferably, it is 0.2 to 1.0% by weight.

In addition, if the synthetic resin molded product has multiple layers, by kneading the additive into the surface layer resin, the effectiveness of the additive can be made faster.
You can reduce the amount used, or mix it into the inner layer to control the amount of bleed and achieve longer-term sustainability. Preferably, the molded product is a thin film with 3 to 5 layers (for example, 5 to 20μ0), and the surface layer is coated with an antifogging agent (A
) and the additive (B) in the inner layer to adjust the abundance ratio on the surface of the synthetic resin molded product. In some cases, both the antifogging agent (A) and the additive (B) are mixed into the inner layer, and the antifogging agent (A) is mixed into the surface layer.
It can be adjusted by mixing. In that case, more favorable results can be obtained in terms of surface contamination and long-lasting effects. To give a specific example, the surface layer is made of polyethylene resin (at least one selected from EVA, LL, VL, etc.) with a thickness of 0.5 to 5 μm, and the inner layer is made of the same type of polyethylene resin. Or other functions (
For example, the inner layer may have a total thickness of 2 to 10 μm, consisting of a mixed composition for imparting stiffness, heat resistance, tear strength, etc., or a multi-layered inner layer for the same purpose.

Further, there is no problem even if other additives are included in advance in addition to the polymeric component. For example, BHT. B} Contains IA, small amounts of inorganic additives, such as colloidal silica, zeolite (powder)
It can also be applied to products containing a small amount of tackifier, etc., or a small amount of tackifier.

The method of the present invention makes it possible for the first time to maintain anti-fogging properties for an extremely long period of time, and its effects are presumed to be based on the following principle.

In other words, when a conventional synthetic resin molded product using only the additive (A) (antifogging agent) is used to package fruits and vegetables, the antifogging property partially deteriorates (water droplets adhere). However, it was discovered that mold was found on the surface of the synthetic resin molded product in that area. On the other hand, when the same experiment was carried out using the synthetic resin molded article of the present invention, not only did the anti-fogging properties not deteriorate and no water droplets were attached, but no mold was observed. This is additive C
This is thought to be due to the effect of B) or the mutual effect of using the antifogging agent (A) and the additive (B) together. Therefore, additives (
Coating only B) on the surface of a synthetic resin molded product,
I conducted a comparative test, but unlike the case of the present invention,
Favorable results were not obtained due to lack of antifogging properties and poor durability.

The reason why the method of the present invention produces such excellent results is that the synergistic effect of the antifogging agent (A) and the additive (B) suppresses the growth of mold and improves the antifogging effect. It is thought that this is due to the fact that the sex can last for a significantly longer period of time. In other words, soil bacteria and other fungi are attached to vegetables, fruits and vegetables, mushrooms, and especially root vegetables, and when these are stored in packaging, they migrate to the surface of the synthetic resin and grow due to the appropriate temperature and humidity inside the packaging. As a result, the antifogging property rapidly deteriorates, but it was discovered that this is prevented in the synthetic resin molded product produced by the method of the present invention, and the problem that was conventionally solved at the end was completely solved. It is.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to this.

Examples 1-7. Comparative Examples 1 to 8 Antifogging agent (A) and additive (B) as shown in Table 1 were blended on the surface of an EVA film with a thickness of 15 μm, and this was dissolved in isobrobyl alcohol. 6 Meyer bar was used to calculate the amount of additive attached to the surface after coating and air drying. On the other hand, using these films, ginger, taro, and lotus root were individually packaged and stored in a constant temperature room at 26°C, and occasionally transferred to an atmosphere at 15°C.
The state of water droplets on the inner surface of the film was observed. The following evaluation points were given according to the degree of adhesion of water droplets, and the results are shown in Table 1.

8 points: No water droplets attached at all 7 points: Water droplets on about 2% of the film area 6
Points...〃10%〃〃〃5 points...
〃20% 〃 〃4 points... 〃30
% 〃 〃3 points... 〃40% 〃
〃2 points... 〃50% 〃 〃1
Points... 〃More than 60% of water droplets Example 8
~1l, Comparative Examples 9-12 As antifogging agent (A), diglycerin monooleate 1
- (DGMO), glycerin monooleate (GMO
) An approximately equal mixture of diglycerol monostearate (DGMS), diethanol beef tallow CG+4-+a) amine as additive (B) at 2:1 or 3, respectively.
:1 ratio, and heated and kneaded with various polymers to prepare master pellets. This was extruded through a circular die to form a film with a thickness of 15 to 20 μm. The total amount of antifogging agent (A) and additive (B) added is 0.
It was 8 to 1.6 wt% (Table 2).

A master pellet was prepared in the same manner using only the antifogging agent (A), and was extruded from a circular die to form a film in the same manner. After each of the obtained films was placed in a 25° C. room for 3 days, the antifogging performance was evaluated, and the results are shown in Table 2. Separately, the surface amount of diethanol tallow amine was measured on those surfaces, and the results are shown in Table 2. Note that the measurement was performed as follows. First, pour 200ml of pure water into a 3001 Erlenmeyer flask. Next, 30c
Cut an m square film sample into 2 cm square pieces and place them in the Erlenmeyer flask. Place on a shaker in a room at 20°C.
Pre-clean for O minutes τ. Divide Finolem into τ portions, transfer 100 ml of Ido to a separating funnel, and add 0. IN sodium acetic acid monoacetate buffer 10mi+, 5g sodium chloride and 3mJ of 0.1% methyl orange solution! Then add 20 mj of chloroform and shake for 3 minutes for extraction. After separating the chloroform layer, the extraction was repeated again using 20 mA of chloroform, and the total volume of the extract was reduced to 50 mA in a volumetric flask.
Set to 1. Using a spectrophotometer, the absorbance at 430 mμ is measured in an IClIl cell with chloroform as a control. On the other hand, using a known concentration of diethanol tallow amine, a calibration curve is prepared in the same manner as above, and the surface concentration of the film is calculated using this.

As briefly mentioned earlier, the continuation of the antifogging properties of the present invention is related to mold, but if the situation is described in more detail, the following facts have become clear. That is, during the test in Comparative Example 1, the part of the film to which the water droplets had adhered was cut out, it was pasted on an agar medium, and the film was incubated at 26°C for 1 hour.
When stored for a week, a white flocculent substance spread throughout the medium in 2 to 3 days. When the medium was further stored for 5 days or more, the entire surface of the medium turned almost blue-green. A little of the blue-green part was scraped off and thoroughly crushed and dispersed in a small amount of water (2 to 3 mR).

A small amount of this dispersion liquid was attached to the surface of the films of Example 8 and Comparative Example 9, and stored at 26° C. in an atmosphere of 100% humidity. After one week, it was taken out, covered with a beaker containing water, and placed in a refrigerator for observation. The film of Comparative Example 9 did not have anti-fog properties and a large amount of water droplets adhered to the area around the area where the dispersion was applied, but the film of Example 8 of the present invention had almost no water droplets attached to the area where the dispersion was applied. However, the anti-fog properties were good. Next, each film was air-dried, and the area around which the dispersion was applied was observed under a microscope.

The situation is shown in Fig. 1, and in the film of Comparative Example 9, filaments were observed in a radial pattern and in the network structure around the area where the dispersion was applied (Fig. 1a). It was about the same or somewhat wider than the range with water droplets. On the other hand, in the case of Example 8 of the present invention, only a slight amount of lint-like material was observed in the area where the dispersion was applied (Figure 1b).
. Considering the above, the bluish-green color on the agar medium is mold spores, and the filamentous matter that formed on the film of Comparative Example 9 must be mold hyphae no matter how you look at it. Additionally, it is conventionally said that wrapping breathable items such as fruits and vegetables will deteriorate the anti-fog properties and cause water droplets to form, but in the above experiment, the fruits and vegetables themselves were not wrapped, so even if this point is taken into consideration, It is proven that there is a 1:1 relationship between the deterioration of anti-fogging properties and the growth of mold. At present, the detailed mechanism is not known, but the method of the present invention ensures that the anti-fogging property lasts for a long period of time, so it must be said that the practical effects of the present invention are extremely large.

Examples 12 to 15, Comparative Example 13 The resin raw material used for the intermediate layer or surface layer was processed using a small extruder (4
Master pellets were prepared by injecting the antifogging agent (A) or additives (B) alone or in combination while extruding at a diameter of 5+nmφ). Each master pellet was mixed with each raw material resin using a drum blender if necessary, and diluted to a target concentration.

Next, each diluted resin etc. was extruded from a five-layer circular die using three extruders to produce a thick tube-shaped film. Subsequently, the material was heated through an annular hot air passage to perform tubular drawing.

The stretched film was cooled, wound up, and stored (aged) at 25°C for 2 days. Next, about 15 pieces of well-washed ginger
0 g was placed in a plastic tray and packaged using an aged film. The packaged product was stored at 25 to 27°C, and after a certain period of time, it was moved to a room at 15°C and the state of adhesion of water droplets was observed. A comparative test was also conducted in the same manner without using the additive (B). The above results are shown in Table 3. Examples 13, 14. No. 15 shows the case where diethanol tallow amine is used as the additive (B) in the inner layer (intermediate layer), and the anti-fogging durability is good and the surface staining is also good.

-4. In Example 16 where diethanol tallow amine was used for the surface layer, both tend to be inferior, but the additive (
The antifogging durability is excellent compared to Comparative Example 13 in which B) is not used.

Table 1-1 DGMO: diglycerin monooleate GMO:
Glycerin monooleate DGMS: Diglycerol monostearate SvcJ: Sorbitan monooleate SMS: Sorbitan monostearate Table 1-2 EΔ~(E.Siethanol Beef tallow (C14-18) Amine fatty (C16-18) acid mono Ester EAI] E-diethanol beef tallow (Cl4-+a) amine fat (C16
~+6) Acid diester Table 1-3 Abbreviations are the same as Table 1-1 Table 1 4 Table 2-1 A: Antifog agent (A): DGMO, GMO. DGM
Mixture B in approximately equal amounts of S: additive (B)/diethanol beef tallow (014-18) amine [Effects of the invention] The synthetic resin molded product of the present invention can maintain its antifogging properties for an extremely long period of time, and is suitable for food products. It is a very useful molded product as it can be stored for a long time when packaged.

[Brief explanation of drawings]

Figure 1 is a diagram showing the growth of mold on the film surface, Figure 1a is the film of Comparative Example 9, and Figure 1b is the film of Example 8.
It is a film of. 1 is the part to which the dispersion was applied, and 2 is the fungal hyphae.

Claims (2)

[Claims] (1) Add 5 to 200 mg/m^ of nitrogen-free nonionic antifogging agent (A) to at least one surface of the synthetic resin molded product.
2 and polyoxyethylene alkylamine represented by general formula I, polyoxyethylene alkylamide, general formula I
At least one additive selected from polyoxyethylene alkylamine fatty acid ester and polyoxyethylene alkylamide fatty acid ester represented by I (B) 1-
A synthetic resin molded product containing a mixed additive consisting of 100mg/m^2. I ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ II ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ However, R is selected from an alkyl group of C_8 to C_2_2, an alkenyl group, or an acyl group having the same group. R' is selected from C_1 to C_2_2 alkyl groups and alkenyl groups. n is 0 to 10, m is 1 to 10 (2) Nitrogen-free nonionic antifogging agent (A) 5-20
mg/m^2, and at least one selected from polyoxyethylene alkylamine represented by general formula I, polyoxyethylene alkylamide, polyoxyethylene alkylamine fatty acid ester represented by general formula II, and polyoxyethylene alkylamide fatty acid ester. A method of imparting antifogging durability to a synthetic resin molded product by making each of 1 to 100 mg/m^2 of one type of additive (B) exist on the surface of the synthetic resin molded product. I ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ II ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ However, R is selected from an alkyl group of C_8 to C_2_2, an alkenyl group, or an acyl group having the same group. R' is selected from C_1 to C_2_2 alkyl groups and alkenyl groups. n is 0 to 10, m is 1 to 10