JP2002317153A - Scratching agent for glass containers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating film having good drying properties, to form a glossy homogeneous coating film after drying, and to whiten even during long-term storage in a cold region or a refrigerator. The present invention provides a coating agent for scratches of a glass container which is excellent in shielding properties and does not need to be applied. (A) General formula: (R ¹ R ² SiO) _m (wherein, R ¹ and R ² are each a monovalent hydrocarbon group selected from the group consisting of an alkyl group, an alkenyl group, and an aryl group. And m is an integer of 3 or more.) And a general formula: R ³ Si
(OR ⁴⁾ ₃ (wherein, R ³ is an alkyl group or an aryl group, R ⁴ is an alkyl group.) Is obtained by reacting the organotrialkoxysilane represented by the presence of equilibration catalyst A coating agent for scratches on a glass container, comprising as a main component an alkoxysilyl-functional organopolysiloxane, (B) an alkylpolysilicate, and (C) a catalyst for promoting a condensation reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scuff coating agent for glass containers such as fruit drink bottles, soft drink bottles, beer bottles, and mineral water bottles. Specifically, the coating has good drying properties, forms a glossy homogeneous coating after drying, and does not whiten during long-term storage in cold regions or refrigerators. The present invention relates to a coating agent for scratches of a glass container which is excellent in quality.

[0002]

2. Description of the Related Art Glass containers such as fruit drink bottles, soft drink bottles, and beer bottles are collected after use and used repeatedly. However, in the bottling process and the distribution process, there is a problem that the surface of the glass container is scratched and the appearance is impaired and the commercial value is reduced.

For this reason, in recent years, various coating agents have been applied to the surface of the glass container to shield the scratches and protect the aesthetic appearance of the glass container.

[0004] As such a coating agent, for example, a coating agent containing a partial hydrolyzate of an organotrialkoxysilane as a main component is known (see JP-A-6-135744). However, although this coating agent has good gloss, appearance, and drying properties, the coating film is slightly hard and brittle, causing cracking during long-term storage in cold regions or refrigerators, resulting in whitening. There was a drawback that there were times.

[0005]

The present inventors have made intensive studies to solve the above problems, and as a result, have reached the present invention.
That is, the object of the present invention is that the coating film has good drying properties, forms a homogeneous coating film having a gloss after drying, and whitens the coating film even during long-term storage in a cold region or a refrigerator. An object of the present invention is to provide a coating agent for scratches of a glass container which is excellent in shielding properties and does not have any problem.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a coating agent for scuffing a glass container, comprising the following components (A) to (C) as main components. (A) General formula: (R ¹ R ² SiO) _m (wherein, R ¹ and R ² are each a monovalent hydrocarbon group selected from the group consisting of an alkyl group, an alkenyl group and an aryl group; Is an integer of 3 or more.) And a general formula: R ³ Si (OR ⁴ ) ₃ (where R ³ is an alkyl group or an aryl group, and R ⁴ is an alkyl 100 parts by weight of an alkoxysilyl-functional organopolysiloxane obtained by reacting an organotrialkoxysilane represented by the following formula in the presence of an equilibration catalyst: (B) 10 to 100 parts by weight of an alkyl polysilicate; C) Condensation reaction accelerating catalyst Catalyst amount

[0007]

DETAILED DESCRIPTION OF THE INVENTION The (A) alkoxysilyl-functional organopolysiloxane used in the present invention has the general formula:
(R ¹ R ² SiO) _m is obtained by reacting a cyclic diorganopolysiloxane represented by _m with an organotrialkoxysilane represented by the general formula: R ³ Si (OR ⁴ ) ₃ in the presence of an equilibration catalyst. It was done. In the cyclic diorganopolysiloxane used, R ¹ and R ² are each a monovalent hydrocarbon group selected from the group consisting of an alkyl group, an alkenyl group and an aryl group. Among these, a methyl group, a vinyl group, and a phenyl group are preferable. m is an integer of 3 or more, and preferably 10 or less. Specific examples of such a cyclic diorganopolysiloxane include hexamethylcyclotrisiloxane, octamethyltetracyclosiloxane, decamethylcyclopentasiloxane, undecamethylcyclohexasiloxane, monovinylheptamethylcyclotetrasiloxane, and 2,6-divinyl. Examples include hexamethylcyclotetrasiloxane, monophenylheptamethylcyclotetrasiloxane, and 2,2-diphenylhexamethylcyclotetrasiloxane. These cyclic siloxanes may be used alone or in combination.

The organotrialkoxysilane used for the component (A) is represented by the above general formula, wherein R ³ is an alkyl group or an aryl group, and is a methyl group, an ethyl group or a phenyl group. Is preferred. R ⁴ is an alkyl group, preferably a methyl group or an ethyl group. Specific examples of such organotrialkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane. These alkoxysilanes may be used alone or in combination.

As the equilibration catalyst used in the reaction between the cyclic diorganopolysiloxane and the organotrialkoxysilane, a basic catalyst or an acidic catalyst usually used for the equilibrium polymerization of diorganosiloxane can be used. Examples thereof include basic catalysts such as potassium hydroxide, potassium silanolate, trimethylammonium hydroxide, and trimethylammonium silanolate; and acidic catalysts such as trifluoromethanesulfonic acid, activated clay, and concentrated sulfuric acid. The equilibration reaction is carried out by adding the catalyst to the cyclic diorganopolysiloxane and the organotrialkoxysilane and then activating the catalyst in a temperature range, for example, 50 to 200.
What is necessary is just to heat in the range of 1 degreeC for 1 to 10 hours.

The (B) alkyl polysilicate is, for example, a polyalkoxysiloxane obtained by hydrolyzing and condensing an alkoxysilane, and specifically includes a partially hydrolyzed condensate of tetramethoxysilane or tetraethoxysilane. The degree of polymerization of these siloxane units is 3 to 20
And more preferably 3 to 10. As the component (B), one kind of such a polysilicate may be used alone, or two or more kinds may be used as a mixture. The amount of component (B) is from 10 to 100 parts by weight, preferably from 20 to 60 parts by weight, per 100 parts by weight of component (A).

As the catalyst for promoting the condensation reaction (C), those conventionally known as catalysts for the condensation reaction of siloxane or silane having a silicon-bonded alkoxy group can be used. For example, in addition to organic acid catalysts such as branched fatty acids, organic tin compounds such as dibutyltin diacetate, dibutyltin dioctate, dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, tin octylate; Isopropyl triisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate,
Organic titanate compounds such as tetraalkyl titanates; organic zirconium compounds such as tetrabutyl zirconate, tetrakis (acetylacetonato) zirconium, tetraisobutylzirconate, butoxytris (acetylacetonato) zirconium, zirconium naphthenate; tris (ethylacetoacetate) ) Organoaluminum compounds such as aluminum and tris (acetylacetonato) aluminum; organometallic catalysts such as zinc naphthenate, cobalt naphthenate and cobalt octylate; amines not containing organosilicon compounds such as diethanolamine and triethanolamine Catalysts and the like. Among these, a branched fatty acid represented by the general formula: C _n H _{2n + 1} COOH is preferred. In the formula, n is an integer of 10 to 26, and is preferably an integer of 11 to 17. Specifically, isoundecanoic acid (n = 10), isolauric acid (n = 11), isotridecylic acid (n = 12), isomyristic acid (n = 13), isopentadecylic acid (n = 14), Palmitic acid (n = 15), isomalgaric acid (n = 1
6), isostearic acid (n = 17), isononadecylic acid (n = 18), isoarachidic acid (n = 19), isoheniicosanoic acid (n = 20), isobenoic acid (n = 21), isotricosanoic acid (n = 22) , Isolignoceric acid (n = 2
3), isopentacosanoic acid (n = 24), isocerotinic acid (n = 25), and isoheptacosanoic acid (n = 26). These fatty acids may be used alone or as a mixture. The amount of the component (C) is a catalytic amount, but is preferably in the range of 0.05 to 20 parts by weight per 100 parts by weight of the component (A), and particularly when a branched fatty acid is used,
The range is preferably 1 to 15 parts by weight, more preferably 3 to 13 parts by weight, per 100 parts by weight of the component (A).

The coating composition of the present invention comprises the components (A) to (C) described above.
Although the component is a component as a main component, it is preferable to mix (D) aminoalkylalkoxysilane in addition to these components. Specifically, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (amino Ethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane. These aminoalkylalkoxysilanes may be used alone or as a mixture.
The addition amount of component (D) is optional, but is preferably in the range of 1 to 20 parts by weight per 100 parts by weight of component (A).

When the coating composition of the present invention is applied to a glass container, it may be used as it is, or may be used after being diluted with an organic solvent such as water, alcohols or hydrocarbons. . As a glass container to which the coating agent of the present invention is applied,
For example, glass bottles such as fruit juice bottles, soft drink bottles, beer bottles, and mineral water bottles may be mentioned. A coating film is obtained by applying the coating agent of the present invention to such a glass container using a cloth, sponge, felt, brush, belt, or the like, followed by drying and solidification.

The coating agent of the present invention as described above is applied to various glass containers and then dried at room temperature in a short time to form a coating film. The resulting coating film is homogeneous and glossy and has excellent appearance, and thus has a feature of hiding a scratch on the surface of a glass container such as a bottle. In addition, since the coating film does not whiten during long-term storage in a cold region or a refrigerator, it has a feature that the shielding property can be maintained.

[0015]

The present invention will be described below in more detail with reference to Examples and Synthesis Examples. In Synthesis Examples 1 and 2, (A)
The component alkoxysilyl-functional organopolysiloxane was synthesized. In the examples, the viscosity is a measured value at 25 ° C., and the performance of the coating film was measured according to the following method. O Concealability It was visually observed whether or not the white of the faint scratches was concealed. ：: No faint scratch was seen. X: Scratches were clearly visible. -Drying property The drying property of the coating film was measured by finger touch. ：: Completely dried and had excellent adhesion. ：: Dry and good adhesion. Δ: Almost dry. X: Undried and sticky. ○ Tactile sensation The finger sensation when the bottle body was grasped by hand was examined. ：: Very good. Δ: Good. X: Insufficient. ○ Appearance The appearance of the coating film, such as the gloss and homogeneity of the coating film, was observed. ：: Very good. X: Insufficient. O P-box whitening property A bottle was placed in a beer plastic case (P-box), and the whitening property of the coating film was observed when the bottle was rotated 10 times while being pressed against a partition plate. ：: No whitening of the coating film was observed. X: The coating film was whitened.

[0016]

Synthesis Example 1 A flask was charged with 740 g of octamethylcyclotetrasiloxane and 20 g of methyltriethoxysilane, and dimethylsiloxane 4 containing 4% by weight of potassium hydroxide.
g was added and the temperature was raised to 180 ° C. Subsequently, 514 g of methyltriethoxysilane was added thereto while maintaining the reflux state.
It was dropped over time. After heating and refluxing for an additional hour, the reflux tube was replaced with a distillation tube, and the reflux temperature was 195 ° C at normal pressure.
The heating was continued until the temperature reached, and volatiles were distilled out of the reaction system. After cooling, the obtained reaction product was measured by gas chromatography.
It was confirmed that the product was an equilibrated reaction product having a distribution of 〜20 weight bodies. Next, a large excess of dry ice was put into the solution, and the generated neutralized salt was removed by filtration to obtain a methoxysilyl-functional methylpolysiloxane. The methylpolysiloxane had a dimethylsiloxane unit (D unit) and a methylsiloxane unit (T unit).

[0017]

Synthesis Example 2 A flask was charged with 740 g of octamethylcyclotetrasiloxane and 20 g of methyltriethoxysilane, and the temperature was raised to 180 ° C. Then add potassium hydroxide
When 0.5 g was added, an increase in solution viscosity due to the equilibration reaction was confirmed. Subsequently, a mixture of 470 g of methyltriethoxysilane and 34.5 g of ethyltrimethoxysilane was added dropwise thereto while maintaining the heating state, and the mixture was completed over 2 hours while maintaining the reflux state. After further heating and refluxing for 1 hour, the reflux tube was replaced with a distillation tube and heating was continued at normal pressure until the reflux temperature reached 195 ° C., and volatiles were distilled out of the reaction system. After cooling, the obtained reaction product was measured by gas chromatography, and as a result, it was confirmed that the reaction product was an equilibrated reaction product having a hexamer peak and a distribution of 3 to 20 weight units. Next, a large excess of dry ice was put into the solution, and the produced neutralized salt was removed by filtration, whereby an alkoxysilyl-functional methylpolysiloxane was obtained. In addition, this methylpolysiloxane
Dimethyl siloxane unit (D unit), methyl siloxane unit (T unit) and ethyl siloxane unit (T unit)
Had.

[0018]

EXAMPLES 1] obtained in Synthesis Example 1 trimethoxysilyl functional methylpolysiloxane 1130 g, ethyl polysilicate, i.e. partial hydrolytic condensate of tetraethoxysilane (average molecular weight 740, SiO ₂ content of 41 wt%, viscosity 3.0 mm ²
/ s, 435 g of specific gravity 1.050), and the mixture was stirred to give a colorless and transparent liquid mixture A (viscosity 3.6 mm ² / s, specific gravity 0.994, refractive index 1.39).
65). The mixture A was mixed with the branched fatty acid and the aminoalkylalkoxysilane in the amounts shown in Table 1 to prepare coating compositions (A-1) to (A-5). These coating agents were applied to a scratched beer bottle (633 ml) using a sponge, and left at room temperature for 3 days. After 3 days, the hiding power, drying property, finger touch, appearance and whitening property of the P box were measured. The results are shown in Table 1. Further, the beer bottle on which the coating film was formed was left in a refrigerator for 2 weeks, and the performance was measured in the same manner as described above. The results are shown in Table 1. As Comparative Example 1, mixture A
Was measured in the same manner as described above, and the results are shown in Table 1.

[0019]

[Table 1]

[0020]

To Example 2 obtained in Synthesis Example 2 alkoxysilyl-functional methylpolysiloxane 1100 g, ethyl polysilicate, i.e. partial hydrolytic condensate of tetraethoxysilane (average molecular weight 740, SiO ₂ content of 41 wt%, viscosity 3.0 mm ²
/ s, specific gravity 1.050) 423 g was added and stirred to give a colorless transparent liquid mixture B (viscosity 4.3 mm ² / s, specific gravity 0.997, refractive index 1.39)
85). This mixture B was blended with the branched fatty acid and the aminoalkylalkoxysilane in the amounts shown in Table 2 to prepare coating compositions (B-1) to (B-5). These coating agents were applied to a scratched beer bottle (633 ml) using a sponge, and left at room temperature for 3 days. After 3 days, the hiding power, drying property, finger touch, appearance and whitening property of the P box were measured. Table 2 shows the results. further,
After the beer bottle on which the coating film was formed was left in a refrigerator for two weeks, its performance was measured in the same manner as described above. The results are shown in Table 2. Further, as Comparative Example 2, the performance of the mixture B was measured in the same manner as described above, and the results are also shown in Table 2.

[0021]

[Table 2]

[0022]

[Comparative Example 3] trimethoxysilyl-functional methylpolysiloxane obtained in Synthesis Example 1, ethyl polysilicate, i.e. partial hydrolytic condensate of tetraethoxysilane (average molecular weight 740, SiO ₂ content of 41 wt%, viscosity 3.0 mm ² / s, specific gravity
1.050), a coating agent (C-) obtained by blending the branched fatty acid and aminoalkylalkoxysilane in the amounts shown in Table 3.
For 1) to (C-3), the performance was measured in the same manner as in Example 1. Table 3 shows the results.

[0023]

[Table 3]

As is clear from Tables 1 and 2, the coating composition of the present invention has good drying properties of the coating film, and has excellent shielding properties without whitening of the coating film even when stored in a refrigerator for a long period of time. Had been maintained. On the other hand, a coating agent having a content of the component (B) outside the range of the present invention may show that even if the component (C) or the component (D) is added, the coating film has insufficient drying properties and finger touch. This was apparent from the results in Table 3.

[0025]

EFFECT OF THE INVENTION The coating composition of the present invention comprises the above component (A)
(C) As a main component, the coating film has good drying properties, forms a glossy homogeneous coating film after drying, and can be used for long-term storage in cold regions or refrigerators. Has the characteristic that it is not whitened and has excellent shielding properties.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Kobayashi 2-2 Chikusa Beach, Ichihara City, Chiba Prefecture Toray Dow Corning Silicone Co., Ltd. R & D Headquarters (72) Inventor Chiba Tomonori Shinagawa-ku Tokyo 5 F-term (reference) in the 10th-18th of Daisan Kogyo Co., Ltd. (reference) 4G059 AA04 AC16 FA22 FB04 FB05 FB06 4J038 DL022 DL031 DL082 JA38 JC35 KA04 LA02 NA01 NA23 PB04 PC03

Claims (5)

[Claims] 1. A coating agent for scratches in a glass container, comprising the following components (A) to (C) as main components. (A) the general ^{formula: (R 1 R 2 SiO)} m ( wherein, R ¹ and R ² is a monovalent hydrocarbon radical selected respectively an alkyl group, from the group consisting of alkenyl groups and aryl groups, m Is an integer of 3 or more.) And a general formula: R ³ Si (OR ⁴ ) ₃ (where R ³ is an alkyl group or an aryl group, and R ⁴ is an alkyl 100 parts by weight of an alkoxysilyl-functional organopolysiloxane obtained by reacting an organotrialkoxysilane represented by the following formula in the presence of an equilibration catalyst: (B) 10 to 100 parts by weight of an alkyl polysilicate; C) Condensation reaction accelerating catalyst Catalyst amount 2. The component (C) has a general formula: C _n H _{2n + 1} CO
The coating agent for scratches on glass containers according to claim 1, wherein the agent is a branched fatty acid represented by OH (where n is an integer of 10 to 26). 3. The coating agent for flaws on glass containers according to claim 1, further comprising 1 to 20 parts by weight of (D) aminoalkylalkoxysilane. It is wherein (A) R ¹ and R ² in component, each a methyl group, a vinyl group or a phenyl group, R ³ is a methyl group, an ethyl group or a phenyl group, R ⁴ is or a methyl group The scratching agent for glass containers according to any one of claims 1 to 3, wherein the agent is an ethyl group. 5. A coating agent for scuffing a glass container according to claim 1, wherein the component (B) is methyl polysilicate, ethyl polysilicate or a mixture thereof. .