JPH0244589B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a method for applying a polymer solution or dispersion, that is, an aqueous polymer liquid, having water as a continuous phase on the surface of a hydrophobic solid. In general, the solid surfaces of glass and synthetic polymer materials, such as some inorganic materials, are strongly hydrophobic, so they are difficult to wet uniformly in systems with high surface tension solvents such as water. It is difficult to apply the liquid. For example, when coating or printing the surface of a molded product made of the above materials using a polymeric substance as a base material, when coating a polymeric substance on a surface modification such as carbon black or pigment, when packaging, photographing, or even magnetic recording. In such cases, such as when coating a polymer substance on the surface of a film to be used as a material, it is difficult to apply an aqueous polymer liquid as the polymer substance. The present invention relates to a method in which, in the above-mentioned case, the aqueous polymer liquid can be applied as it is to a practically sufficient extent without the need for the assistance of a surface-active substance. <Conventional technology and its problems> When applying a polymer substance to the surface of a hydrophobic solid,
There is also a method of applying the organic solvent solution or dispersion, but this method has risks such as fire and explosion, is toxic, has equipment limitations, and has economical problems, so it is difficult to use the polymer material. A method of applying an aqueous polymer liquid is desired and is in practice. This type of conventional method involves applying an aqueous polymer solution containing a surface-active substance, but there is also a method in which the surface of the hydrophobic solid is activated by corona treatment or plasma treatment. However, the addition of surface-active substances may reduce the properties such as water resistance and moisture resistance of the applied hydrophobic polymer coating film due to its hydrophilicity, or if it is a low-molecular-weight surface-active substance, Softening point of applied coating film,
There are many problems such as a decrease in physical properties such as the glass transition point and strength, and a decrease in the adhesion between the coating film and the surface of the hydrophobic solid, which may migrate to the surface and impair the appearance. . In addition, simply corona treatment or plasma treatment of the surface of a hydrophobic solid often does not allow the water-based polymer liquid to sufficiently wet the surface of the hydrophobic solid, and there are problems in that it is often impossible to treat the surface due to the shape. be. <Problems to be Solved by the Invention and Means for Solving the Problems> The present invention solves the conventional problems as described above. However, in view of the above-mentioned circumstances, the present inventors have conducted intensive research on a method for applying an aqueous polymer liquid to the surface of a hydrophobic solid without adding any organic solvent or surfactant. The present inventors have discovered that the desired effect can be obtained by pretreating the surface of a solid solid with a specific aqueous sol, regardless of whether or not a surface-active substance is added, and the present invention has been completed. That is, in the present invention, when applying a solution or dispersion of a polymer substance having water as a continuous phase to the surface of a hydrophobic solid, the surface of the hydrophobic solid is partially coated with a water-dispersed inorganic colloid having a positive surface charge in water. The present invention relates to a method for applying an aqueous polymer liquid, which is characterized by pretreatment with an aqueous sol that has been made hydrophobic. In the present invention, specific examples of water-dispersed inorganic colloids include alumina sol, tin oxide sol, iron oxide sol, and the like. Among them, alumina sol is useful because of its good effect expression and ease of industrial availability, and the alumina sol can be used as it is as it is commercially available as an aqueous dispersion. For example,
Examples include Alumina Sol-100, Alumina Sol-200, Alumina Sol-520 (all manufactured by Nissan Chemical Co., Ltd.), Cataloid AS-1, Cataloid AS-2 (both manufactured by Catalyst Kasei Co., Ltd.), and the like. The gist of the present invention is to pre-treat the surface of a hydrophobic solid with an aqueous sol in which a water-dispersed inorganic colloid having a positive surface charge in water is partially hydrophobized as described above. There are various methods that can be considered, but among them, the most important ones are the method of partially hydrophobizing the water-dispersed inorganic colloid by a contact reaction using active groups on the surface, and the method of partially hydrophobicizing the water-dispersed inorganic colloid. On the other hand, there is a method of partially hydrophobicizing it with a negative ionic species or a water-dispersed inorganic colloid having a negative surface charge. Specifically, as a method using a contact reaction using active groups on the surface of a water-dispersed inorganic colloid, at least one
A method in which a silane derivative having silanol groups and/or a condensate thereof is subjected to a catalytic reaction is preferred.

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[Formula] (However, R ¹ to ^{R 3} are organic groups) These silane derivatives and/or condensates thereof are produced by converting the corresponding raw material compounds such as silyl halides, alkoxysilanes, and γ-alkoxyalkoxysilanes into acids or It can be easily obtained by heating and hydrolyzing in the presence of an alkali or in the absence of a catalyst, if necessary. For example, raw material compounds corresponding to () include trimethylchlorosilane, trimethylmonomethoxysilane, etc.
Raw material compounds corresponding to () include dimethyldimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-glycidoxypropyldimethoxysilane, etc. Raw material compounds corresponding to () include methyltrimethoxysilane, methyltriethoxysilane, etc. Silane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltri(methoxyethoxy)silane, vinyltriacetoxysilane, γ-chloropropyltripropoxysilane,
γ-Mercaptopropyltriethoxysilane, γ
-glycidoxypropyltrimethoxysilane, γ
- Methacryloxytriethoxysilane, phenyltrimethoxysilane, etc., and raw material compounds corresponding to () include tetramethoxysilane, tetraethoxysilane, etc. During the catalytic reaction, the weight ratio of the water-dispersed inorganic colloid to the aforementioned silane derivative and/or its condensate (both calculated as active ingredients) is usually 100/0.1 to 100/50.
It is better to This is because if the amount of the silane derivative and/or its condensate is too large, the resulting aqueous sol tends to become too hydrophobic, whereas if it is too small, the resulting aqueous sol tends to be less effective. Such a catalytic reaction may be carried out by hydrolyzing the above-mentioned raw material compound in advance to obtain a corresponding silane derivative and/or a condensate thereof, and adding a water-dispersed inorganic colloid thereto for the catalytic reaction, or The raw material compound and the water-dispersed inorganic colloid as described above may be directly mixed and subjected to a catalytic reaction in parallel with the hydrolysis. Appropriate conditions for the catalytic reaction vary depending on the structure and concentration of the silane derivative and/or its condensate used, as well as the reaction temperature and time, but for example, alumina sol and methyltriethoxysilane are directly mixed and hydrolysis When conducting contact reactions in parallel,
20 to 30°C for 10 days or more or 50°C for 20 hours or more. In the method of partially hydrophobicizing a water-dispersed inorganic colloid with a negative ion species, it is preferable to use an organic acid salt as the negative ion species. Examples of such organic acid salts include monocarboxylic acids such as acetic acid, butyric acid, valeric acid, cabroic acid, benzoic acid, and P-toluic acid, dicarboxylic acids such as adipic acid and terephthalic acid, metasulfonic acid, propanesulfonic acid, etc. alkyl sulfonic acids, sulfosuccinates such as dipropylsulfosuccinate and diisobutysulfosuccinate, phosphonic acids such as methylphosphonic acid, propylphosphonic acid, and phenylphosphonic acid, organic acids such as lithium, sodium, potassium, etc. There are alkali metal salts and ammonium salts. When partially hydrophobicizing a water-dispersed inorganic colloid with the above-mentioned negative ion species, the weight ratio of both (both calculated as active ingredients) usually differs depending on the type of negative ion species used, etc. The water-dispersed inorganic colloid/the above-mentioned organic acid salt ratio is preferably 100/1 to 2/1. If there are too many negative ionic species, the resulting aqueous sol tends to become too hydrophobic;
Conversely, if this amount is too small, the resulting aqueous sol tends to be less effective. In addition, in a method of partially hydrophobicizing a water-dispersed inorganic colloid with another water-dispersed inorganic colloid having a negative surface charge, silica sol or antimony oxide sol can be used as the other water-dispersed inorganic colloid; But silica sol is better. Examples of such silica sols include commercially available acidic silica sols and basic silica sols. In this case, the weight ratio of both (both in terms of active ingredients) is usually preferably from 10/1 to 2/5 (water-dispersed inorganic colloid/silica sol). The reason is the same as when using the organic acid salt described above. A preferred method for obtaining an aqueous sol by partially hydrophobicizing a water-dispersed inorganic colloid has been described above, but it is even more effective to combine the two methods. Among these, preferred is a method in which the above-mentioned silane derivative and/or its condensate is brought into contact in the first step, and then the above-mentioned organic acid salt is brought into contact in the second step. In this case, if the water-dispersed inorganic colloid is alumina sol, the weight ratio of both in the first stage (both calculated as active ingredients) should be alumina sol/silane derivative and/or condensate thereof = 100/0.1 to
100/50, and the weight ratio in the second stage (both in terms of active ingredients) was changed to the treated product in the first stage/
It is preferable that the organic acid salt is 100/1 to 2/1. This is because, in the above weight ratio range, on the one hand, better stability of the resulting aqueous sol can be ensured, and on the other hand, the aqueous sol exhibits better effects. <Function, etc.> The present invention is an aqueous sol in which a water-dispersed inorganic colloid having a positive surface charge in water is partially hydrophobized,
This is applied to the surface of a hydrophobic solid for pretreatment, and then a water-based polymer liquid is applied to the surface of the hydrophobic solid. Although the surface of the hydrophobic solid may be dried between both coatings, the effects of the present invention can be fully achieved even without drying. It is also effective to wash the hydrophobic solid surface with water between both applications, regardless of whether or not the drying is performed. There are no particular restrictions on the type, molecular weight, polymerization form, etc. of the polymeric substance of the aqueous polymeric liquid to be applied in the present invention, and there is no particular restriction on whether it is made into an aqueous solution or an aqueous dispersion. Examples of such polymeric substances include dihydric carboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, and 5-sulfoisophthalic acid, and ethylene glycol, diethylene glycol,
Polyesters obtained from dihydric alcohols such as neopentyl glycol, 1,4-butanediol, and polyethylene glycol, methoxymethylated nylon, polyamides obtained from polyamines and dihydric carboxylic acids such as dimer acid, etc. Condensation polymers such as ethylene, propylene, styrene, vinyl acetate, vinylidene chloride, etc.
Polymers made by appropriately copolymerizing these polyaddition type polymers, as well as vinyl monomers such as maleic anhydride, styrene sulfonate, and vinyl pyrrolidone, and acrylic monomers such as methyl methacrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, and acrylamide. etc. In order to make the polymer substances exemplified above into an aqueous polymer liquid, an appropriate amount of a hydrophilic monomer such as 5-sulfoisophthalate, styrene sulfonate, or hydroxyethyl acrylate is copolymerized with the molecular chain of the polymer substance. A method of making the polymer substance itself water-soluble or water-dispersible, or emulsion polymerization using a small amount of a surface-active substance during polymerization of the polymer substance,
There are methods to make water-based latex. The resulting aqueous polymer liquid may contain an ionic or nonionic organic low-molecular compound, or even an inorganic compound. The means for applying the aqueous sol and aqueous polymer liquid in the present invention is not particularly limited, and may be applied by dipping, spraying, etc. in addition to coating using various coaters. In addition, the concentration of those active ingredients at the time of application depends on the content of the aqueous sol, such as the type of aqueous polymer liquid, etc.
Furthermore, it is influenced by the properties required for the product after application, but in the case of an aqueous sol it is usually 0.01 to 10% by weight, preferably 0.05 to 5% by weight, and in the case of an aqueous polymer liquid it is usually 0.5% by weight. The content is preferably ~20% by weight. <Examples, etc.> In each of Examples 1 to 17, an aqueous sol was prepared under the conditions listed in Table 1 or 2, and the aqueous sol was applied to a hydrophobic solid surface (in the table) under the conditions listed in Table 3. Table 4 shows the evaluation results of the resulting coating film. The preparation procedure for the aqueous sol and the evaluation criteria for the coating film are as follows. (1) Partial hydrophobization using a silane derivative and/or its condensate: Water-dispersed alumina sol or titanium oxide sol (both effective concentration 10% by weight, same hereinafter) and its raw material compound corresponding to the silane derivative and/or its condensate The mixture was stirred at 20° C. for 1 hour for hydrolysis, followed by a contact reaction under the conditions listed in Table 1 or 2, followed by dilution with water. (2) Partial hydrophobization with organic acid salt or silica sol: A diluted aqueous solution of organic acid salt or silica sol was added to water-dispersed alumina sol under the conditions listed in Table 1 or 2 to prepare. (3) Partial hydrophobization using a silane derivative and/or its condensate and an organic acid salt: In the first step, the catalytic reaction is carried out as in (1), and in the second step, an organic acid salt is added as in (2). It was prepared by adding a dilute aqueous solution of the acid salt. (a) Evaluation 1 (Applicability): The applicability of the aqueous polymer liquid applied under the conditions listed in Table 3 was visually evaluated using the following criteria. 1...Causes a repelling phenomenon when applied 2...Causes a repelling phenomenon when drying with hot air 3...Causes a slight repelling phenomenon when drying with hot air 4...Does not cause a repelling phenomenon, but the coating film is uneven 5... Does not cause a repelling phenomenon at all (b) Evaluation 2 (Appearance of paint film): The appearance of the paint film was evaluated with the naked eye according to the following criteria. ◎…Good 〇…Interference fringes are slightly observed △…Interference fringes are observed ×…Coating film cannot be obtained due to poor coating properties (c) Evaluation 3 (Adhesion): The adhesion of the coating film was tested by tape peeling test. It was evaluated based on the following criteria. 1... The proportion of the part that remains without peeling is less than 10% 2... The proportion of the part that remains without peeling is 10 to 50
Less than % 3…The percentage of the part that remains without peeling is 50 to 90
Less than % 4...The percentage of the part that remains without peeling is 90~
Less than 100% 5...The proportion of the part that remained without peeling was 100% In addition, each Comparative Example 1 to 8 was based on each of the above examples,
An aqueous sol was prepared under the conditions listed in Table 5 (however,
(not a partially hydrophobized aqueous sol as in the present invention), the aqueous sol and water-based polymer liquid were applied sequentially under the conditions listed in Table 6, and the evaluation results are shown in Table 7. Ta. However, Comparative Examples 1 to 5
No aqueous sol was prepared and therefore no pretreatment was performed.

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[Table] Disodium.

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[Table] Therefore, it cannot be evaluated.
<Effects of the Invention> The excellent effects of the present invention are clear from the evaluation results in Table 4 relative to Table 7. Since it is possible to apply a water-based polymer liquid to the surface of a hydrophobic solid without any problem, it is possible to apply a water-based polymer liquid to the surface of a hydrophobic solid. It is effective for coating latexes, etc., which do not have sufficient adhesion due to their small amount.

Claims (1)

[Claims] 1. When applying a solution or dispersion of a polymer having water as a continuous phase to the surface of a hydrophobic solid, the surface of the hydrophobic solid is coated with a water-dispersed inorganic colloid having a positive surface charge in water. A method for applying an aqueous polymer liquid, characterized by pretreatment with a partially hydrophobic aqueous sol. 2. The method for applying an aqueous polymer liquid according to claim 1, wherein the water-dispersed inorganic colloid is an alumina sol. 3. The method for coating an aqueous polymer liquid according to claim 2, wherein the aqueous sol is partially hydrophobized with a silane derivative and/or a condensate thereof having at least one silanol group in the molecule. 4 Claim 2 in which the aqueous sol is partially hydrophobized with one or more organic acid salts
Method for applying the aqueous polymer liquid described in Section 1. 5. The method for applying an aqueous polymer liquid according to claim 2, wherein the aqueous sol is partially hydrophobized with silica sol. 6 The aqueous sol is partially hydrophobized by contacting a silane derivative and/or its condensate having at least one silanol group in the molecule, and then contacting one or more organic acid salts. A method for applying an aqueous polymer liquid according to claim 2.