JP3106079B2 - Silicone emulsion composition for coating of synthetic resin film or sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicone emulsion composition for coating a synthetic resin film or sheet, and more particularly to an aqueous silicone emulsion composition useful as a release agent for such a film or sheet.

[0002]

2. Description of the Related Art Most of synthetic resin films or sheets (hereinafter referred to as films, etc.) have excellent moldability and water resistance, and are therefore widely used as packaging materials for various foodstuffs. The thermoplastic resin film or the like is wound in a roll shape in the manufacturing process, and when used as a packaging material for foodstuffs, the film or the like wound in a roll shape is formed into a cup or bag shape while rewinding. However, there was a problem that the surfaces of the resin films and the like adhered to each other, the rewinding could not be carried out smoothly, and the films and the like would be torn if pulled strongly. Also, when manufacturing a large number of containers from a film or the like, when trying to store an article in a container formed by stacking a large number of films and punching, the peelability between molded products is poor, resulting in a decrease in work efficiency, There was a drawback that the molded product was damaged if it was strongly peeled off. As a means for solving this problem, an emulsion of a silicone release agent is applied to the surface of the film or the like.

Recently, a styrene-based resin film or the like has been subjected to a corona discharge treatment in advance to further impart anti-fogging properties (see JP-A-53-115781). Sucrose fatty acid esters have been added to silicone release agents (Japanese Patent Publication No. 63-62538).
Reference). However, since the surfaces of these synthetic resin films and the like are extremely hydrophobic, it is difficult to uniformly wet water or an emulsion, and therefore, when an emulsion-type release agent is applied, application unevenness occurs, and a molded article is formed. In this case, there is a problem that the appearance is poor.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an organopolysiloxane emulsion release which can be uniformly applied to the surface of a synthetic resin film or the like and which does not impair the transparency of the film or the like. Agent composition.

[0005]

Means for Solving the Problems The present invention relates to a silicone emulsion composition for coating a synthetic resin film or the like which has solved the above-mentioned problems. This silicone emulsion composition is represented by the following general formula (I): 1 to 60% by weight of an organopolysiloxane having a viscosity of 10 to 1,000,000 centistokes at 25 ° C.

Embedded image (Where R ¹ is a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms,
One or two groups selected from unsubstituted or halogen-substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R ² has 1 carbon atom
One or two or more groups selected from an unsubstituted or halogen-substituted monovalent hydrocarbon group of -20, and n is an integer of 10-3,000. (B) 0.1 to 20% by weight of a nonionic surfactant (C) 0.1 to 10% by weight of an anionic surfactant (D) Consisting of the remaining components of water , the average particle size of the emulsion of the component (A) Diameter 5
It is an emulsified composition having a particle size of not more than 00 μm.

The organopolysiloxane used as the component (A) in the present invention is represented by the general formula [I]. Here, examples of the alkoxy group having 1 to 6 carbon atoms in R ¹ include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a pentoxy group, a hexoxy group, and the like. . Examples of the unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 20 carbon atoms in R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. Group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-tetradecyl group, n-hexadecyl group, n-octadecyl Alkyl groups such as groups, cycloalkyl groups such as cyclopentyl group and cyclohexyl group, aryl groups such as phenyl group and tolyl group, and part or all of the hydrogen atoms bonded to carbon atoms of these groups were substituted with halogen atoms Groups, such as a 3,3,3-trifluoropropyl group. In the present invention, it is desirable that 90 mol% or more of R ¹ and R ² is a methyl group.

Further, the organopolysiloxane has a temperature of 25 ° C.
Is required to be in the range of 10 to 1,000,000 centistokes, and if it is lower than 10 centistokes, the obtained composition does not show sufficient mold releasability, and for example, the composition is applied to a styrene resin film or the like. When applied, good releasability cannot be imparted to the surface. Also
If it is larger than 1,000,000 centistokes, the resulting composition will become sticky when applied to a film or the like. Preferably it is 100 to 100,000 centistokes.

The organopolysiloxane as the component (A) is preferably obtained by an emulsion polymerization method. The emulsion polymerization method includes a method of polymerizing an organosiloxane in an aqueous medium using a strong acid or strong alkali as a polymerization catalyst (see Japanese Patent Publication No. 34-2041), alkylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, aliphatic sulfonic acid, A method of polymerizing an organosiloxane in an aqueous medium using a silylalkyl sulfonic acid, an aliphatic substituted diphenyl ether sulfonic acid, an alkyl hydrogen sulfate or the like as a polymerization catalyst (JP-B-41-13995, Belgian Patent No. 686812, U.S. Pat. Alternatively, a diorganosiloxane trimer to hexamer is emulsified and dispersed in an aqueous solution of a salt type surfactant, and an ion exchange resin is added to the dispersion to carry out ion exchange of the salt type surfactant. ,
There is a method of polymerizing a diorganosiloxane in an aqueous medium (see Japanese Patent Publication No. 54-19440).

The amount of the organopolysiloxane of component (A) is from 1 to 60% by weight. If the amount is less than 1% by weight, sufficient release properties are imparted when applied to a synthetic resin film or the like. If the amount is more than 60% by weight, the viscosity of the emulsified composition will be too high, making it difficult to handle, and will cause stickiness when applied to a synthetic resin film or the like. Preferably, it is in the range of 10 to 40% by weight.

As the nonionic surfactant of the component (B), polyoxyethylene higher alcohol ether, polyoxyethylene alkyl phenyl ether, sorbitan monoalkylate, sorbitan trialkylate, polyoxyethylene sorbitan monoalkylate, polyoxyethylene Examples thereof include sorbitan trialkylate, polyoxyethylene sorbitol tetraalkylate, and glycerol monoalkylate, which can be used alone or in combination of two or more. In addition to the surfactant, a fluorine-based surfactant or a silicone-based nonionic surfactant can also be used.
It is preferable that LB is in the range of 1.5 to 20, particularly preferably in the range of 7.0 to 15.0. The amount of the component (B) is in the range of 0.1 to 20% by weight.
If the amount is less, the wettability to a synthetic resin film or the like cannot be sufficiently improved. If the amount is more than 20% by weight, the viscosity of the emulsified composition becomes too high, so that the handling becomes difficult. This is because the transparency and the releasability of the film when applied are reduced. Preferably it is in the range of 1 to 10% by weight.

The anionic surfactant (C) is mainly contained as a neutralizing salt of the polymerization catalyst in the target emulsified composition, and includes sodium lauryl sulfate, ammonium lauryl sulfate, Examples thereof include sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dialkyl sulfosuccinate, potassium alkyl phosphate, sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, sodium polyoxyethylene tridecyl ether sulfate, and the like. . The compounding amount of the component (C) is in the range of 0.1 to 10% by weight, which is 0.1% by weight.
If the amount is less, the storage stability of the emulsified composition is lowered and separation becomes easy.In addition, the wettability to a synthetic resin film or the like cannot be sufficiently improved, and 10
If it is more than 10% by weight, when applied to a synthetic resin film or the like,
This is because white turbidity is easily caused, and a whitening phenomenon is easily caused. Preferably it is in the range of 0.5 to 5% by weight.

The emulsion composition of the present invention is obtained by dispersing the organopolysiloxane of the component (A) in water using the nonionic surfactant of the component (B) and the anionic surfactant of the component (C). The emulsified composition must have an average particle size of 500 mμ or less. This is because, when the average particle diameter is larger than 500 μm, when applied to a synthetic resin film or the like, the transparency of the film or the like tends to be impaired. Particularly preferably, the average particle size is
300 mμ or less. Generally, the smaller the average particle size, the better the transparency of the film or the like. The average particle size of the emulsion is 500 mμ or less, especially by using the emulsion polymerization method.
It is possible to obtain an emulsified product having an extremely fine particle dispersion of 400 μm or less, and the emulsified composition of the present invention can be prepared using this emulsified product. The average particle size can be adjusted by adjusting the type and amount of the surfactant used in the emulsion polymerization, the stirring power, and the like.

The emulsion composition of the present invention is used as it is after neutralizing the emulsion of component (A) obtained from the raw material of component (A) by emulsion polymerization. It can be manufactured by a method. According to this method, the steps are advantageously simplified. The polymerization conditions for emulsion polymerization are not particularly limited.For example, when a low molecular weight organopolysiloxane is emulsified and dispersed in water using a salt type anionic surfactant, and then polymerization is performed using an ion exchange resin. (See JP-A-63-275640), if the mixture is heated to an appropriate temperature after the addition of the ion exchange resin, or is appropriately stirred with another polymerization catalyst such as a strongly acidic substance or a strongly alkaline substance. Good. In this case, since the obtained emulsion is acidic or alkaline, it is practically desirable to neutralize it by a conventional method.

The emulsified composition of the present invention further comprises an antifogging agent,
Various additives known per se, such as a wettability improver and a preservative, can be blended. For example, an anti-fog agent is formed by molding a film or sheet coated with an emulsified composition into a food packaging container, filling the content, and then blending it to prevent clouding of the container wall due to water vapor generated from the content. Is what is done. Examples of such anti-fogging agents include HL
Surfactants and sucrose fatty acid esters having a high B value are known.

The emulsified composition of the present invention obtained as described above is extremely useful as a release agent for a synthetic resin film or the like. For example, the content of the component (A) is 0.1 to 2.0% by weight. Diluted with water as before. The coating amount is generally 0.01 to 1.0 g / m ² on a dry basis, especially 0.02 to
0.2 g / m ² is preferred. If the amount is less than 0.01 g / m ² , sufficient releasability cannot be obtained, and if the amount is more than 1.0 g / m ² , transparency may be impaired, and stickiness may become remarkable. Application to a synthetic resin film or the like is performed by, for example, applying the diluted emulsion composition to the film or sheet surface by roller application or the like, homogenizing the coating with an air knife or the like, and then drying in an oven. It is. Next, the present invention will be described in detail with reference to practical examples, but the present invention is not limited thereto.
In addition,% in an example shows weight%.

[0016]

EXAMPLES The emulsified compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 3 shown below were each diluted 100 times with deionized water, and the following characteristics were examined. 1) Average particle size Measured by auto-correlation spectroscopy. 2) Surface tension The surface tension was measured by a platinum plate method using a CBVP surface tensiometer manufactured by Kyowa Science Co., Ltd. 3) Wettability to Sheet One side of a biaxially oriented polystyrene sheet having a thickness of 0.21 mm was coated with a Mayer bar # 3, and the degree of wetting was visually observed. Evaluation ：: Good without repelling at all, Δ: Slight repelling,
×: High repellency 4) Transparency of sheet After drying the polystyrene sheet coated with the emulsified composition as described above at room temperature for 3 hours or more, each sheet was treated with 3
Laminated and fixed, turbidity meter [Nippon Denshoku Industries Co., Ltd.]
Was used to measure the haze value.

Example 1 A 10% aqueous solution of lauryl sulfate (110.7 g) was gradually added dropwise to a mixture of 332.2 g of octamethylcyclotetrasiloxane and 0.76 g of hexamethyldisiloxane with a homomixer at a low speed while stirring. Stop and stir at 3,00
After increasing to 0 rpm and high-speed stirring for about 15 minutes, the remaining aqueous lauryl sulfate solution and 557.84 g of deionized water were added for dilution.
Next, this was subjected to secondary emulsification at a pressure of 300 kg / cm ² using a high-pressure homogenizer, and then left at 50 ° C. for 20 hours to carry out a polymerization reaction. An aqueous solution of sodium (29.9 g) was added for neutralization, followed by filtration with a cotton cloth to obtain an emulsion of dimethylpolysiloxane as the component (A). 100 g of this emulsion is weighed, dimethylpolysiloxane is extracted by adding isopropyl alcohol, and the extracted oil is washed with water and dried to obtain a dimethylpolysiloxane having a viscosity of 25,000 at 25 ° C.
cSt. 40 g of polyoxyethylene octyl phenyl ether (EO added mole = 9, HLB = 13.6) as component (B) and sodium polyoxyethylene nonyl phenyl ether sulfate (EO) as component (C) were added to the remaining 931.4 g of the emulsion. 35% aqueous solution of added mole number = 3) 2
When 8.6 g of the mixture was mixed and dissolved by low-speed stirring with a homomixer for about 20 minutes, a milky white emulsified composition was obtained (Table 1 shows the composition of each component, but the same applies to the following examples). This emulsion composition was homogeneous with an average particle size of 230 μm, and did not show any layer separation even after being left at room temperature for one month, showing high stability. Various properties of the obtained emulsion composition are shown in Table 2 (the same applies to the following examples).

Example 2 A milky white emulsified composition was obtained in the same manner as in Example 1 except that the 10% aqueous solution of lauryl sulfate in Example 1 was replaced with a 10% aqueous solution of dodecylbenzenesulfonic acid. In the same manner as in Example 1, 100 g of the dimethylpolysiloxane was weighed out after neutralization with sodium carbonate and extracted with isopropyl alcohol. The viscosity of dimethylpolysiloxane at 25 ° C. was 23,000 cSt. This emulsified composition had a uniform average particle size of 210 μm, and showed no layer separation even after being left at room temperature for one month, indicating that the composition was highly stable.

EXAMPLE 3 450.9 g of octamethylcyclotetrasiloxane, 1.04 g of hexamethyldisiloxane, 10% aqueous solution of lauryl sulfate 112.
7g, 290.98g of deionized water and 10% sodium carbonate aqueous solution
Using 30.4 g, an emulsion of dimethylpolysiloxane was obtained as the component (A) in exactly the same manner as in Example 1. 100 g of this emulsion was weighed and extracted with isopropyl alcohol, and the viscosity of the obtained dimethylpolysiloxane was measured. The result was 23,000 cSt at 25 ° C. This emulsion 78
In the same manner as in Example 1, 100 g of polyoxyethylene lauryl ether (mol number of added EO = 8, HLB = 12.1) and 114 g of a 35% aqueous solution of sodium polyoxyethylene nonylphenyl ether sulfate (mol number of added EO = 3) were added to 6.02 g. To obtain a milky white emulsion composition. This emulsified composition was homogeneous with an average particle size of 200 μm,
No layer separation was observed even after standing for a period of 5 months, indicating a high stability.

Example 4 110.1 g of octamethylcyclotetrasiloxane, 0.25 g of hexamethyldisiloxane, 110% aqueous solution of lauryl sulfate 110.
1 g, 837.05 g of deionized water and 10% sodium carbonate aqueous solution
Using 29.73 g, an emulsion of dimethylpolysiloxane as the component (A) was obtained in exactly the same manner as in Example 1. 100 g of this emulsion was weighed, extracted with isopropyl alcohol, and the viscosity of the dimethylpolysiloxane obtained was 22,000 cSt at 25 ° C. This emulsion 98
To 7.23 g, 10 g of polyoxyethylene oleyl ether (EO addition mole number = 20, HLB = 13.6) and 2.9 g of 35% aqueous solution of sodium polyoxyethylene nonylphenyl ether sulfate (EO addition mole number = 3) as in Example 1. To obtain a milky white emulsified composition. This emulsion composition had a uniform average particle size of 250 μm, and showed no layer separation at all even after being left at room temperature for one month, and was highly stable.

Example 5 332.2 g of octamethylcyclotetrasiloxane, 0.76 g of hexamethyldisiloxane, 10% aqueous solution of lauryl sulfate 110.
7g, 557.84g of deionized water and 10% sodium carbonate aqueous solution
Using 29.9 g, an emulsion of dimethylpolysiloxane as the component (A) was obtained in exactly the same manner as in Example 1. 100 g of this emulsion was weighed and extracted with isopropyl alcohol, and the viscosity of the obtained dimethylpolysiloxane was measured. The result was 23,000 cSt at 25 ° C. The emulsion 931.
4 g of polyoxyethylene octyl phenyl ether (E
Number of moles of O added = 9, HLB = 13.6) 40 g, ammonium polyoxyethylene nonylphenyl ether sulfate (EO
A milky white emulsion composition was obtained by mixing 28.6 g of a 35% aqueous solution of the added mole number = 3) in the same manner as in Example 1. This emulsion composition was homogeneous with an average particle size of 230 μm, and did not show any layer separation even after being left at room temperature for one month, showing high stability.

Example 6 332.2 g of octamethylcyclotetrasiloxane, 4.76 g of hexamethyldisiloxane, 10% aqueous solution of lauryl sulfate 110.
7 g, 553.8 g of deionized water and 10% aqueous sodium carbonate solution 3
An emulsion of dimethylpolysiloxane as the component (A) was obtained in the same manner as in Example 1 using 0.0 g. Perform isopropyl alcohol extraction on 100 g of this emulsion,
When the viscosity of the obtained dimethylpolysiloxane was measured, it was 340 cSt at 25 ° C. To 931.46 g of this emulsion, 40 g of polyoxyethylene sorbitan monooleate (mol number of added EO = 20, HLB = 15.0) and 28.6 g of a 35% aqueous solution of sodium polyoxyethylene nonylphenyl ether sulfate (mol number of added EO = 3) were added. By mixing in the same manner as in Example 1, a milky white emulsion composition was obtained. This emulsified composition was homogeneous with an average particle size of 240 μm, had no layer separation even after being left at room temperature for one month, and was highly stable.

Example 7 332.2 g of octamethylcyclotetrasiloxane, 0.32 g of hexamethyldisiloxane, 10% aqueous solution of lauryl sulfate 110.
7g, 558.28g of deionized water and 10% sodium carbonate aqueous solution
An emulsion of dimethylpolysiloxane as the component (A) was obtained in the same manner as in Example 1 by using 29.9 g. 100 g of this emulsion was weighed, extracted with isopropyl alcohol, and the extracted oil was washed with water and dried. The viscosity of the dimethylpolysiloxane obtained after drying was 98,000 cSt at 25 ° C. 40 g of polyoxyethylene octyl phenyl ether (EO addition mol = 9, HLB = 13.6) was added to 931.4 g of the remaining emulsion.
A milky white emulsion composition was obtained by mixing 28.6 g of a 35% aqueous solution of sodium polyoxyethylene nonylphenyl ether sulfate (number of moles of EO added = 3) in the same manner as in Example 1. This emulsion composition was homogeneous with an average particle size of 230 μm, and did not show any layer separation even after being left at room temperature for one month, showing high stability.

Comparative Example 1 An emulsion of dimethylpolysiloxane as the component (A) was obtained in exactly the same manner as in Example 1. 28.6 g of a 35% aqueous solution of sodium polyoxyethylene nonylphenyl ether sulfate (EO addition mole number = 3) as the component (C)
Alone to obtain a milky white emulsified composition. This emulsion composition was homogeneous with an average particle size of 230 μm and had high storage stability, but was poor in wettability to a polystyrene sheet.

Comparative Example 2 300 g of dimethylpolysiloxane having a viscosity of 25,000 cSt at 25 ° C. and 80 g of polyoxyethylene octyl phenyl ether (mol number of added EO = 9, HLB = 13.6) were weighed in a polyethylene container, and were weighed in a polyethylene mixer. The mixture was mixed with high speed stirring for 5 minutes. Then add 620g of deionized water
Is slowly dropped while stirring at low speed, phase inversion is stopped when the viscosity is increased, the stirring speed is increased to 3,000 rpm, and high-speed stirring is performed for about 15 minutes, and then the remaining deionized water is added to dilute the milky white color. An emulsion composition was obtained. This emulsion composition had an average particle size of 530 μm, and no separation was observed even after being left at room temperature for one month. However, the emulsified composition was inferior in wettability to a polystyrene sheet and also inferior in sheet transparency. I was

Comparative Example 3 300 g of dimethylpolysiloxane having a viscosity of 25,000 cSt at 25 ° C. and 40 g of polyoxyethylene octyl phenyl ether (mol number of added EO = 9, HLB = 13.6) were weighed in a polyethylene container, and were weighed with a homomixer. The mixture was mixed with high speed stirring for 5 minutes. Then add 602.9 g of deionized water
Was slowly dropped while stirring at a low speed, and when the phase inversion and thickening were stopped, the stirring speed was increased to 3,000 rpm, and the mixture was stirred at high speed for about 15 minutes, and then diluted with the remaining deionized water. Further, a 35% aqueous solution of sodium polyoxyethylene nonylphenyl ether sulfate (number of moles of EO added = 3) 5
The milky white emulsion composition was obtained by mixing 7.1 g. This emulsion composition has an average particle size of 550 mμ because it is not based on the emulsion polymerization method.
No separation was observed even after standing at room temperature for one month, but the transparency was poor when applied to a polystyrene sheet.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

The silicone emulsion composition according to the present invention comprises:
Since the wettability to the surface of a synthetic resin film or the like is extremely excellent, it is useful as a release agent when molding using such a resin film or the like, and since it becomes a uniform coating film, the transparency of the synthetic resin film or the like is improved. There is no risk of damage. Therefore, it is suitable for use in products whose appearance is important, such as resin sheets for food packaging containers.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Morizou Nakazato 1-10, Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Inside the Silicone Electronics Materials Research Laboratory, Shin-Etsu Chemical Co., Ltd. (56) References JP-A-5-295264 (JP, A) JP-A-4-178429 (JP, A) JP-A-4-84643 (JP, A) JP-A-57-151649 (JP, A) JP-A-61-230734 (JP, A) JP 45-10057 (JP, B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 1/00-201/10

Claims (2)

(57) [Claims] (A) 1 to 60% by weight of an organopolysiloxane represented by the following general formula [I] and having a viscosity at 25 ° C. of 10 to 1,000,000 centistokes: (Where R ¹ is a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms,
One or two groups selected from unsubstituted or halogen-substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R ² has 1 carbon atom
One or two or more groups selected from an unsubstituted or halogen-substituted monovalent hydrocarbon group of -20, and n is an integer of 10-3,000. (B) 0.1 to 20% by weight of nonionic surfactant (C) 0.1 to 10% by weight of anionic surfactant (D) Consisting of the balance of water , the average particle size of the emulsion of component (A) being 500 mμ. A silicone emulsion composition for coating a synthetic resin film or sheet characterized by the following. Wherein said component (A) is a synthetic resin film or sheet for coating the silicone emulsion composition according to請<br/> Motomeko 1, characterized in that the organopolysiloxane obtained by emulsion polymerization .