JP5962984B2 - Antifogging agent, antifogging coating composition and coated article thereof - Google Patents

Description

The present invention relates to an antifogging agent derived from a raw material derived from a natural product, an antifogging coating composition, and a coated article thereof. In particular, the present invention relates to an antifogging coating composition that can impart antifogging properties to the surface of a transparent plastic material or glass material, and a coated article thereof.

Conventionally, when the surface of a molded product or the like (transparent plastic material, glass material, or the like) is dewed or water vapor or the like adheres to the surface of the molded product, there is a problem that the surface of the molded product becomes cloudy and visibility is lowered. In order to prevent the fogging phenomenon from occurring, a method is known such as coating the surface with a hydrophilic substance to impart antifogging properties. Specifically, a method of applying a surfactant, a method of kneading a surfactant into a base resin, a method of applying a hydrophilic inorganic filler such as silica or titanium oxide, a hydrophilic inorganic filler and a surface activity The method of mixing and apply | coating an agent or water-soluble polymer is mentioned. However, in these methods, generally, the hydrophilic substance tends to flow out of the surface of the molded article due to the attached water droplets, and thus the problem that the antifogging property is not maintained is pointed out.

As one type of the surfactant, a rosin surfactant is known, and for example, it is described that it can be used as a hydrophilic coating film component for an aluminum fin material (see, for example, Patent Document 1). However, this document does not describe any specific constitution of the rosin surfactant.

Patent Document 2 discloses that a compound obtained by adding an alkylene oxide to a rosin resin and further subjecting it to sulfation and neutralization can be used as an emulsifying dispersant for an aqueous emulsion. Further, the emulsifying dispersant is an alkylphenol-based resin. It is described that there is no concern as an endocrine disrupting substance found in surfactants.

In addition, as an antifogging paint, there is an attempt to maintain antifogging properties for a long period of time by making use of crosslinking reactivity and curing by heating (for example, see Patent Document 3). However, when an anti-fogging coating is applied to an object having low heat resistance, a usage mode that does not involve a heat crosslinking reaction may be preferable.

  Therefore, there is a strong demand for the development of a new antifogging agent that is free from concerns about endocrine disrupting substances and has excellent antifogging effect maintainability, as in the case of conventionally known rosin surfactants.

Japanese Patent Laid-Open No. 04-278188 JP 2002-11337 A JP 2003-105255 A

The present invention provides a novel antifogging agent that uses a natural product-derived raw material from the viewpoint of environmental considerations and that satisfies the above requirements, and applies the antifogging agent to a coating composition or a coated article. With the goal.

The present inventor has paid attention to the applicability of the polymerized rosin derivative in order to solve the problems of the conventional technology. That is, intensive studies were conducted focusing on the correlation between the purity of the polymerized rosin and / or its lower ester used and the physical properties of the reaction product obtained and the anti-fogging property and maintenance of the intended coating composition. Repeated. As a result, an addition reaction product of a polymerized rosin having a specific dimer content and an alkylene oxide, a polymerized rosin having a specific dimer content and / or a lower ester thereof, and a specific polyalkylene glycol It has been found that an antifogging agent containing a condensation reaction product as a main component can solve the above problems, and has completed the present invention.

That is, the present invention provides a reaction product (1) having an average addition mole number of alkylene oxide obtained by adding alkylene oxide to polymerized rosin having a dimer content of 60% by weight or more. The present invention relates to an antifogging agent characterized by containing as a main component. Further, the present invention provides at least a polymer rosin having a dimer content of 60% by weight or more and / or a polymer lower rosin ester selected from the group consisting of polyethylene glycol, polypropylene glycol, and an ethylene oxide-propylene oxide copolymer. The present invention relates to an antifogging agent comprising as a main component a reaction product (2) having a weight average molecular weight of 1000 to 6000 obtained by condensing one kind of polyalkylene glycol. The present invention also relates to an antifogging coating composition comprising the antifogging agent. Furthermore, the present invention relates to a coated article formed by applying the antifogging coating composition.

According to the present invention, an antifogging agent that is environmentally friendly and excellent in various properties can be provided. The antifogging agent obtained by the present invention is useful as a blending component for preparing an antifogging coating composition. That is, the antifogging agent is free from fear of endocrine disrupting substances as in the case of conventionally known rosin surfactants, and can maintain the antifogging effect for a longer period. Therefore, the antifogging coating composition and a coated article formed by applying the antifogging coating composition are excellent in the various performances and contribute to the purpose of environmental protection.

In the antifogging agent of the present invention, the reaction products (1) and / or (2) described below are essential.

The reaction product (1) is obtained by adding alkylene oxide to a polymerized rosin having a dimer content of 60% by weight or more, preferably 80% by weight or more so that the average number of added moles is 5-50. It is obtained. The average number of moles added refers to the average number of moles of alkylene oxide added per mole of carboxyl groups in the polymerized rosin. As alkylene oxides that are constituents of the reaction product (1), considering the performance of the resulting antifogging agent (antifogging property, maintainability), any one of ethylene oxide and propylene oxide is used alone. Or it is preferable to use these in combination.

The reaction product (2) has a polymer rosin and / or polymerized rosin lower ester having a dimer content of 60% by weight or more, preferably 80% by weight, polyethylene glycol, polypropylene glycol, and ethylene oxide- It is obtained by condensing with at least one polyalkylene glycol selected from the group consisting of propylene oxide copolymers, and has a weight average molecular weight of 1000 to 6000. The polyalkylene glycols are hereinafter referred to as specific polyalkylene glycols. “Lower” in the polymerized rosin lower ester means a methyl, ethyl or propyl group. Hereinafter, the polymerized rosin and the lower ester may be collectively referred to as “specific polymerized rosins”.

As the specific polymerized rosin used in the present invention, it is more preferable to use a polymerized rosin starting from distilled rosin or the hydride when the color tone is important in the intended use. It does not specifically limit as a manufacturing method of specific polymerization rosin, A well-known various method is employable.

The molecular weight of the polyalkylene glycol, which is a component of the reaction product (2), is not particularly limited, but usually a weight average molecular weight of 300 to 3000, preferably 500 to 2000 can be used.

The reaction product (1) can be easily produced using a specific polymerization rosin and an alkylene oxide and employing a known addition reaction method. Specifically, a specific polymerization rosin is charged into a pressure-resistant reaction vessel, heated to about 150 to 200 ° C. and melted, and then an alkylene oxide is added in the presence of water and a catalyst (such as potassium hydroxide). The reaction is gradually introduced into the reaction vessel, and the addition reaction proceeds under a pressure of less than 1 MPa at about 120 to 180 ° C.

The proportion of the specific polymerization rosin and alkylene oxide used in the addition reaction is selected so that the number of added moles of alkylene oxide in the obtained reaction product (1) is about 5 to 50, preferably 15 to 40. That's fine. When the added mole number of the reaction product (1) is less than 5, the antifogging agent containing the reaction product (1) as a main component has insufficient antifogging property, and the added mole number is 50. In the case where it exceeds 1, the hydrophilicity of the reaction product (1) tends to be low, and the maintainability of the antifogging agent that can be obtained tends to decrease. Further, the acid value of the reaction product (1) is not particularly limited, but is preferably 3 mgKOH / g or less, more preferably 1 mgKOH / g or less from the viewpoint of antifogging property and maintenance of the obtained antifogging agent. preferable.

The reaction product (2) can be easily produced by a known esterification method using a specific polymerized rosin and a specific polyalkylene glycol. Specifically, under high temperature conditions of about 150 to 300 ° C., it is performed while removing the produced water out of the system, but if air is mixed during the esterification reaction, the reaction product (2) may be colored, It is preferable to carry out under an inert gas such as nitrogen or helium. In the reaction, it is not always necessary to use an esterification catalyst. However, in order to shorten the reaction time, acid catalysts such as acetic acid and paratoluenesulfonic acid, metal hydroxides such as calcium hydroxide, calcium oxide, and magnesium oxide are used. A metal oxide such as can also be used.

The use ratio of the specific polymerized rosins and the specific polyalkylene glycols in the condensation reaction of the reaction product (2) cannot be uniquely determined, but the ratio between the carboxyl group of the specific polymerized rosins and the hydroxyl group of the specific polyalkylene glycols. The amounts used of both components are determined so that the equivalent ratio (equivalent of COOH group / equivalent of OH group) is usually 1 / 0.9 to 1 / 1.2, preferably 1/1 to 1 / 1.1. do it. The molecular weight of the reaction product (2) is determined from the antifogging property and the maintenance property of the antifogging agent obtained by using this, and is about 1000 to 6000, preferably 2000 to 5000 in terms of weight average molecular weight. Is done. The acid value of the reaction product (2) is not particularly limited, but is preferably 3 mgKOH / g or less and more preferably 1 mgKOH / g or less from the viewpoint of the antifogging property of the antifogging agent and the maintenance property.

  In addition, the terminal hydroxyl group of reaction product (1), (2) can also be blocked as needed. As the blocking means, acetylation with acetic anhydride, urethanization with isocyanate, sulfonation with sulfur trioxide, sulfate esterification with sulfuric acid and the like can be applied.

  The antifogging agent of the present invention contains the reaction product (1) and / or (2) as a main component, and the content is 50% by weight or more, preferably 70% by weight. % Or more. Therefore, in the antifogging agent of the present invention, in consideration of the antifogging performance of the obtained antifogging coating resin composition and the coated article, if it is less than 50% by weight, various known antifogging agents (if necessary) Surfactants, water-soluble polymers, etc.), water resistance agents (carbodiimides, isocyanates, water-soluble metal chelates, metal alkoxides, silane coupling agents, etc.), leveling agents, antifoaming agents, UV absorbers, antioxidants, antibacterials An agent, an antifungal agent, an inorganic filler, a colorant, a solvent, and the like may be appropriately blended.

The anti-fogging coating composition of the present invention only needs to contain the anti-fogging agent of the present invention as an anti-fogging blending component, and there are no particular restrictions on the form of applied paint, the type of coating resin used, etc. Not. The coating composition to which the antifogging agent of the present invention is applied is not limited to water-based paints such as emulsion paints and water-soluble paints, and can be suitably used for various non-water-based paints. For example, as the water-based paint, those using a hydrophilic resin such as polyvinyl alcohol, acrylamide polymer, acrylic acid / acrylic ester copolymer, and modified cellulose as a binder are preferable. There is no special limitation about manufacture of this coating material, A well-known method is applicable. In addition, when various additives are previously mix | blended in the anti-fogging agent of this invention, it is not necessary to mix | blend these additives repeatedly at the time of preparation of an anti-fog coating composition. The blending ratio of the antifogging agent of the present invention in the antifogging coating composition of the present invention is not particularly limited and can be appropriately determined according to the applied coating, but is usually about 10% by weight in terms of solid content. Hereinafter, it is preferably used at 1 to 7% by weight.

  The object to be coated with the anti-fogging coating composition of the present invention is not particularly limited, and may be various known molding materials, articles, and substrates. For example, the plastic molded product can be applied to molded products obtained from various commonly used plastic materials. As an object to be coated other than the plastic material, for example, an inorganic base material such as glass or various metals can be targeted.

When the article to be coated is a plastic sheet or film, a coated article having excellent antifogging properties can be easily obtained by applying and drying the antifogging coating composition of the present invention according to a conventional method. The method for applying and drying the antifogging coating composition of the present invention is not particularly limited, and may be appropriately selected and determined according to the object to be applied. For example, various known coating methods such as spraying, coater, dipping, and brushing can be employed according to the material of the object to be coated, and various drying methods such as room temperature drying and forced drying can be applied.

Hereinafter, the present invention will be described more specifically with reference to production examples, examples, and comparative examples, but the present invention is not limited to these examples. Parts and% are based on weight unless otherwise specified.

Production Example 1 (Synthesis of reaction product (1))
A pressure-resistant reaction vessel equipped with a stirrer, thermometer, nitrogen introduction tube, gas introduction tube and diversion tube was charged with 100 parts of polymerized rosin having a dimer content of 60% and 1 part of potassium hydroxide as a reaction catalyst. Under heating to 170 ° C., the polymerized rosin was melted. While maintaining the same temperature, 440 parts of ethylene oxide gas was gradually introduced into the reaction vessel to carry out an addition reaction, and a reaction product (1-1) having an average addition mole number of ethylene oxide of 30 and an acid value of 2.5 mgKOH / g. Got.

Production Example 2 (Synthesis of reaction product (1))
In Production Example 1, in place of the polymerized rosin (dimer content: 60%), the same amount of polymerized rosin having a dimer content of 80% was used, and the amount of ethylene oxide gas introduced was increased to 510 parts. Carried out an addition reaction in the same manner to obtain a reaction product (1-2) having an average ethylene oxide addition mole number of 35 and an acid value of 2.0 mgKOH / g.

Comparative Production Example 1 (Synthesis of Comparative Reaction Product)
In Production Example 1, an addition reaction was carried out in the same manner except that the same amount of Chinese rosin was used instead of 100 parts of the polymerized rosin, and a comparative reaction having an ethylene oxide average addition mole number of 32 and an acid value of 2.0 mgKOH / g Product 1 was obtained.

Comparative Production Example 2 (Synthesis of Comparative Reaction Product)
In Production Example 1, an addition reaction was performed in the same manner except that the same amount of a polymer rosin having a dimer content of 40% was used instead of the polymer rosin, and the average number of moles of ethylene oxide added was 36, and the acid value was 2.0 mgKOH. / G of comparative reaction product 2 was obtained.

Production Example 3 (Synthesis of reaction product (2))
In a reactor equipped with a cooling pipe, a water separator, a stirrer and a nitrogen introduction pipe, 300 parts of polymerized rosin having a dimer content of 60% (equivalent of COOH group: 1.0) and a weight average molecular weight of 1000 Polyethylene glycol (550 parts) (OH group equivalent of 1.1) was added and melted by heating, and 2 parts of triphenyl phosphite was added dropwise over 15 minutes while maintaining the temperature at about 150 ° C. After completion of dropping, the temperature was raised to 280 ° C. and kept for 5 hours, and then 50 g of xylene was added and refluxed. While removing the reaction product water with a water separator, the esterification reaction was carried out for 14 hours. Subsequently, unreacted substances and xylene were distilled off under reduced pressure to obtain a reaction product (2-1) having a weight average molecular weight of 3300 and an acid value of 2.0 mgKOH / g.

Production Example 4 (Synthesis of reaction product (2))
In Example 1, the same amount of polymerized rosin having a dimer content of 80% was used instead of 300 parts of the polymerized rosin, and polyethylene glycol having a weight average molecular weight of 2000 instead of 550 parts of polyethylene glycol having a weight average molecular weight of 1000. A condensation reaction was carried out in the same manner except that 1100 parts (equivalent of COOH group: 1.1) were used to obtain a reaction product (2-2) having a weight average molecular weight of 4800 and an acid value of 2.5 mgKOH / g. .

Comparative Production Example 3 (Synthesis of Comparative Reaction Product)
In Example 1, a condensation reaction was carried out in the same manner except that the same amount of polymerized rosin having a dimer content of 40% was used instead of 300 parts of the polymerized rosin, and the weight average molecular weight was 3100, and the acid value was 2.5 mgKOH. A comparative reaction product 3 was obtained.

Examples 1-4 (Preparation of antifogging agent and antifogging coating composition)
23.3 parts of soft water was added to and dissolved in 10 parts of each reaction product obtained in Production Examples 1 to 4 to obtain 30% solids aqueous solutions (the aqueous solutions are referred to as antifogging agents 1 to 4 in order). ). The hydrophilic polymer (methacrylamidopropyltrimethylammonium chloride / methoxypolyethylene glycol methacrylate / cyclohexyl methacrylate / methacrylic acid = 10/35/50/5 (parts) with respect to 16.7 parts (5 parts solids) of the antifogging agent. ) Was mixed to obtain an antifogging coating composition (in order, referred to as antifogging coating compositions 1 to 4).

Examples 5-8 (Manufacture of coated articles)
The anti-fogging coating compositions 1 to 4 are spray-coated on the base material A (transparent acrylic resin plate) and the base material B (transparent glass plate), respectively, dried by heating (80 ° C. × 15 minutes), and coated with a film thickness of 20 μm. An article was obtained.

Comparative Examples 1 to 3 (Preparation of comparative antifogging agent and comparative antifogging coating composition)
10 parts of each comparative reaction product obtained in Comparative Production Examples 1 to 3 was added with 23.3 parts of soft water and dissolved to obtain each aqueous solution with a solid content of 30%. Referred to as agents 1-3). By mixing 250 parts of the hydrophilic polymer with 16.7 parts of the antifogging agent, comparative antifogging coating compositions were obtained (referred to as comparative antifogging coating compositions 1 to 3 in order).

Comparative Examples 4 to 6 (Manufacture of coated articles)
The antifogging coating compositions 1 to 3 for comparison were spray-coated on the substrate A and the substrate B, respectively, and dried by heating (80 ° C. × 15 minutes) to obtain a coated article having a film thickness of 20 μm.

(Evaluation Examples 1 to 8 and Comparative Evaluation Examples 1 to 6)
Coating film performance test conditions and evaluation methods are as follows. Each evaluation result is shown in Table 1.

Exhalation anti-fogging property:
Exhalation was blown at room temperature, and the presence or absence of cloudiness was visually evaluated. The case where cloudiness was not recognized was rated as ◯, the case where slight cloudiness was recognized as Δ, and the case where considerable cloudiness was observed as ×.

Steam defogging:
The coating film was continuously irradiated with 40 ° C. steam, and the presence or absence of cloudiness after 1 hour and 8 hours was visually evaluated. The case where cloudiness was not observed and a smooth water film was formed was marked with ◎, the case where cloudiness was not observed but the water film was not smooth and rough, and the cloudiness was recognized as x.

Adhesion:
JIS K
The presence or absence of peeling of the coating film was visually evaluated in accordance with 5400 8.5.1. The case where peeling was not recognized at all was rated as “◯”, the case where slight peeling was observed as “Δ”, and the case where considerable peeling was observed as “×”.

From Table 1, the antifogging coating composition comprising the antifogging agent of the present invention is antifogging and antifogging as compared with the comparative antifogging coating composition comprising the comparative antifogging agent. It is clear that the effect is excellent in terms of maintainability (steam defogging after 8 hours) and the like.

Claims (9)

The reaction product (1) having an average addition mole number of alkylene oxide obtained by adding alkylene oxide to polymerized rosin having a dimer content of 60% by weight or more is contained as a main component. An antifogging agent characterized by that. The antifogging agent according to claim 1, wherein the reaction product (1) is formed using a polymerized rosin having a dimer content of 80% by weight or more. The antifogging agent according to claim 1 or 2, wherein the reaction product (1) has an acid value of 3 mgKOH / g or less. The antifogging agent according to any one of claims 1 to 3, wherein the alkylene oxide is ethylene oxide and / or propylene oxide. At least one polyalkylene selected from the group consisting of polymerized rosin having a dimer content of 60% by weight or more and / or the polymerized rosin lower ester, polyethylene glycol, polypropylene glycol, and ethylene oxide-propylene oxide copolymer An antifogging agent comprising, as a main component, a reaction product (2) having a weight average molecular weight of 1000 to 6000 obtained by condensing with glycols. The antifogging agent according to claim 5, wherein the reaction product (2) comprises a polymerized rosin and / or a polymerized rosin lower ester having a dimer content of 80% by weight or more. The antifogging agent according to claim 5 or 6, wherein the reaction product (2) has an acid value of 3 mgKOH / g or less. An antifogging coating composition comprising the antifogging agent according to any one of claims 1 to 7. A coated article obtained by applying the antifogging coating composition according to claim 8.