JPH08199115A - Water-based composite resin dispersion - Google Patents

Abstract

PURPOSE: To obtain a water-based composite resin dispersion capable of forming a transparent, homogeneous and readily and easily handleable film excellent in water resistance and mold releasability. CONSTITUTION: This resin dispersion contains 10-70 pts.wt. polyester resin, 0.1-20 pts.wt. silicone compound, 0.1-5 pts.wt. surfactant, 2-30 pts.wt. water-soluble organic compound and 20-87.8 pts.wt. water so as to provide 100 pts.wt. sum total of the polyester resin, silicone compound, surfactant, water-soluble organic compound and water. The polyester resin has at least one anionic polar group, 40-200 deg.C softening point and 1500-30000 number-average molecular weight. At least a part of the silicone compound is covered and wrapped in particles of the polyester resin. The surfactant is a nonionic and/or an anionic surfactants and the boiling point of the water-soluble organic compound is 60-200 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a novel aqueous composite resin dispersion, which is suitably used as a coating agent for various information recording materials such as a release coating agent for image recording media and a back coating agent for magnetic recording media. Regarding More specifically, the present invention relates to a water-based composite resin dispersion that is transparent and homogeneous, has excellent water resistance and releasability, and can form a coating film that is easy and easy to handle.

[0002]

2. Description of the Related Art Textile products, paper, plastic films,
BACKGROUND ART Various resin compositions have been conventionally used as coating agents such as paints, inks, adhesives, surface treatment agents, etc. used for surface coating of metals and the like. Currently, from the viewpoint of environmental pollution prevention, safety, and effective use of resources,
(1) Solid type, (2) Non-aqueous dispersion type, (3)
A resin composition such as an aqueous dispersion type and (4) a solventless type is drawing attention, and each of them is under development depending on its characteristics. Among the above resin compositions, the aqueous dispersion type is the most versatile because it is easy and easy to handle, and it is expected that the demand will be expanded.

In this aqueous dispersion, various dispersions using a polyester resin have been proposed and put into practical use. Generally, in an aqueous dispersion, it is necessary to impart excellent water dispersibility to a resin, and in a dispersion using a polyester resin, in order to disperse the polyester resin in water, a sulfonate metal base-containing compound, A polyester resin in which hydrophilic raw materials such as polyalkylene glycol and an aliphatic carboxylic acid are copolymerized singly or in a combination of two or more kinds is used. However, when such a copolymerization component is used to impart water dispersibility, water resistance is generally lowered. As a measure for preventing a decrease in water resistance, for example, in Japanese Patent Publication No. Sho 61-58092, 0.5 to 10 mol% of a sulfonic acid metal group-containing aromatic dicarboxylic acid is copolymerized with respect to the total acid component of a polyester resin. However, it is disclosed that a water-soluble organic compound having a boiling point of 60 to 200 ° C. is used as a dispersion aid.

Further, when an aqueous dispersion of polyester resin is used as a coating agent for various information recording materials,
In addition to forming a coating film having the above excellent water dispersibility and excellent water resistance, a coating film that simultaneously satisfies excellent releasability, transparency, uniformity, or mechanical properties. There is a need for an aqueous dispersion of a polyester resin that forms

A simple method for improving the releasability of a coating film obtained from an aqueous dispersion of polyester resin is a method of mixing another aqueous resin or an aqueous additive with the aqueous dispersion of polyester resin. As an aqueous resin having excellent releasability, for example, an aqueous emulsion compound such as a silicone emulsion compound is mixed with an aqueous dispersion of a polyester resin. However, in general, the water-based dispersion contains a water-soluble organic compound as a dispersion aid in order to impart water dispersibility and water resistance, and therefore when such an aqueous emulsion compound is mixed with the water-based dispersion. The aqueous emulsion compound aggregates due to the presence of the water-soluble organic compound which is a dispersion aid. Therefore, by simply adding the dispersion aid and the aqueous emulsion compound at the same time, the desired releasability cannot be obtained in the coating film obtained from the aqueous dispersion of the polyester resin. Further, since the above-mentioned aqueous emulsion compound aggregates, the coating film obtained from such an aqueous dispersion has a problem that it is not transparent and homogeneous.

[0006]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned conventional problems, and an object thereof is to:
An object of the present invention is to provide an aqueous composite resin dispersion having excellent water dispersibility, which is transparent and homogeneous, has excellent water resistance and releasability, and can form a coating film which is easy and easy to handle. .

[0007]

The aqueous composite resin dispersion of the present invention comprises 10 to 70 parts by weight of a polyester resin, 0.1 to 20 parts by weight of a silicone compound, and 0.1% by weight of a surfactant.
˜5 parts by weight, 2 to 30 parts by weight of the water-soluble organic compound, and 20 to 87.8 parts by weight of water, and
An aqueous composite resin dispersion containing the polyester resin, the silicone compound, the surfactant, the water-soluble organic compound, and the water in an amount of 100 parts by weight.
The polyester resin has at least one kind of anionic polar group, and the polyester resin has a softening point of 40 to 20.
0 ° C., the number average molecular weight of the polyester resin is 1500 to
30,000, at least a part of the silicone compound is encapsulated in particles of the polyester resin, the surfactant is a nonionic surfactant and / or an anionic surfactant, and the water-soluble The boiling point of the organic compound is 60 to 200 ° C.

In a preferred embodiment, the water-based composite resin dispersion of the present invention contains 10 to 50 parts of the above polyester resin.
Parts by weight, 0.1 to 5 parts by weight of the silicone compound, 0.1 to 1 part by weight of the surfactant, 2 to 25 parts by weight of the water-soluble organic compound, and 19 to 87.8 parts by weight of water. And the polyester resin, the silicone compound, the surfactant, the water-soluble organic compound, and the water are contained in an amount of 100 parts by weight.

The polyester resin used in the aqueous composite resin dispersion of the present invention can be prepared by a usual method by appropriately combining a polycarboxylic acid, a glycol compound and a compound having an anionic polar group.

Examples of the polycarboxylic acid used for preparing the polyester resin include terephthalic acid, isophthalic acid, orthophthalic acid, 2,3-naphthalic acid, 1,1,
3-trimethyl-3-phenylindene-4,5-dicarboxylic acid, p- (hydroxyethoxy) benzoic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, fumaric acid, maleic acid, tetrahydrophthalic acid And dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid. Like the dicarboxylic acid,
Tri and tetracarboxylic acids such as trimellitic acid, pyromellitic acid and the like may also be used.

Examples of the glycol compound include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, Triethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanedimethanol, tricyclodecane dimethylol, bisphenol A ethylene oxide or propylene oxide adduct, hydrogenated bisphenol A ethylene oxide Adduct or propylene oxide adduct, 2,2-
Examples include diethyl-1,3-propanediol and 2-n-butyl-2-ethyl-1,3-propanediol.

As the anionic polar group,

[0013]

Embedded image

(Wherein M ₁ and M ₂ each represent a hydrogen atom, an alkali metal atom, a tetraalkylammonium group, or a tetraalkylphosphonium group, and M ₃ to M ₆ each independently represent A hydrogen atom, an alkali metal atom, a monovalent hydrocarbon group, or an amino group, and R ₁ to R ₆ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group) .

Examples of the compound capable of forming the above-mentioned anionic polar group include the following: As the compound forming -COOM ₁ , the above-mentioned polycarboxylic acid, glyceric acid or dicarboxylic acid which is an acid component of polyester is used. Oxycarboxylic acids such as methylolpropionic acid, N, N-dimethanolglycine, hydroxyethylbenzoic acid, aminocarboxylic acids such as diaminopropionic acid, diaminobenzoic acid and derivatives thereof; as a compound forming -SO ₃ M _2. Is
Polycarboxylic acids and derivatives thereof such as 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium, sulfoisophthalic acid, sodium sulfosuccinic acid, sodium sulfohydroquinone and alkylene oxide adducts, and sodium sulfobisphenol A and alkylene oxide adducts The phosphorus-containing compound includes compounds represented by the following formulas.

[0016]

Embedded image

Anionic polar groups can be introduced into the polyester resin by adding and reacting these compounds at any stage before the completion of the polymerization reaction.

The above polyester resins may be used alone or in combination of two or more if necessary, and the total amount of the above polyester resin, silicone compound, surfactant, water-soluble organic compound and water (hereinafter referred to as a dispersion mixture). ) 10 to 70 parts by weight, preferably 10 to 50 parts by weight, and more preferably 25 to 35 parts by weight in 100 parts by weight. If the content is less than 10 parts by weight, the viscosity will be too low.
Problems such as popping occur during application. If it exceeds 70 parts by weight, the viscosity becomes too high, and it is difficult for it to flow when used as a coating liquid, and defects such as streaks occur in the coating film.

The above polyester resin is essentially amorphous and has a softening point of 40 to 200 ° C., preferably 60 to 200 ° C.
It is in the range of 180 ° C. When the softening point is less than 40 ° C,
The resulting coating film has high tackiness and is not easy and easy to handle.
If the softening point exceeds 200 ° C, excellent water dispersibility cannot be obtained. If the polyester resin is crystalline,
In the resulting water-based composite resin dispersion, the polyester resin easily causes phase separation, so that the water-based composite resin dispersion having excellent storage stability cannot be obtained.

Further, the polyester resin has a number average molecular weight of 1,500 to 30,000, preferably 3,000.
The range is up to 20000. When the number average molecular weight is less than 1500, the mechanical properties of the resulting coating film, particularly flexibility, are insufficient. When the number average molecular weight exceeds 30,000, the viscosity of the water-based composite resin dispersion becomes high, making it difficult to increase the content of the polyester resin, and further increasing the amount of heat required for drying increases the processing cost. To do.

The anionic polar group concentration in the polyester resin of the present invention is preferably 5 to 4000 equivalents, more preferably 10 to 3000 equivalents, and most preferably 20 to 1000 equivalents per 10 ⁶ g of the resin. When the concentration of the anionic polar group is less than 5 equivalent / 10 ⁶ g, excellent water dispersibility cannot be obtained. When the concentration of the anionic polar group exceeds 4000 equivalent / 10 ⁶ g, the polyester resin becomes water-soluble, so that the water resistance of the coating film deteriorates.

The silicone compound used in the water-based composite resin dispersion of the present invention is used to improve the releasability from various substrates lacking in polyester resin.

Examples of the above silicone compound include various modified silicone oils such as amino modified, epoxy modified, carboxyl modified, carbinol modified, methacryl modified, mercapto modified, phenol modified, polyether modified, methylstyryl modified, higher fatty acid modified, Examples include higher alkoxy-modified and fluorine-modified silicone oil.

The above silicone compound is used in the dispersion mixture 1
0.1 to 20 parts by weight, preferably 0.1 to 100 parts by weight
˜5 parts by weight, more preferably 0.1 to 3 parts by weight. When the content is less than 0.1 parts by weight, the releasability of the polyester resin is not improved. If it exceeds 20 parts by weight, the excess silicone compound causes phase separation, so that an aqueous resin dispersion having excellent storage stability cannot be obtained.

A part of the silicone compound is encapsulated in the particles of the polyester resin. Here, being encapsulated means that at least a part of the silicone compound component is completely encapsulated in the polyester resin particles. That is, at least a part of the silicone compound component is incorporated in the network of polyester molecular chains forming the polyester resin particles. As a result, a coating film having improved dispersion stability and excellent releasability can be obtained.

The surfactant used in the aqueous composite resin dispersion of the present invention is used for mixing the polyester resin and the silicone compound in an excellent dispersed state. As the above-mentioned surfactant, a nonionic surfactant and an anionic surfactant can be used alone or in combination.

Examples of the above nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and fatty acid monoglyceride.

Examples of the anionic surfactant include fatty acid salt, alkyl sulfate ester salt, alkylbenzene sulfonate, alkylnaphthalene sulfonate, dialkylsulfosuccinate, alkyl diallyl ether sulfonate, alkyl phosphate and naphthalene sulfone. Examples thereof include acid formalin condensates, aromatic sulfonic acid formalin condensates, polyoxyethylene alkyl sulfate ester salts, and polyoxyethylene alkyl allyl ether sulfate ester salts.

The above-mentioned surfactant is contained in an amount of 0.1 to 5 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of the dispersion mixture. When the content is less than 0.1 part by weight, the polyester resin and the silicone compound cannot be mixed in an excellent dispersed state. Therefore, the polyester resin aggregates and precipitates in the aqueous composite resin dispersion. If it exceeds 5 parts by weight, the water resistance of the resulting coating film is reduced.

The water-soluble organic compound used in the aqueous composite resin dispersion of the present invention has a function of increasing the affinity of the polyester resin for water and assisting the water dispersibility thereof.

The above water-soluble organic compound is an organic compound having a solubility of 20 g or more in 1 liter of water at 20 ° C., and examples thereof include aliphatic and alicyclic alcohols, ethers, esters, and ketone compounds. The boiling point of this water-soluble organic compound is 60 to 200 ° C.,
It is preferably in the range of 70 to 160 ° C. Boiling point is 60
When the temperature is lower than 0 ° C, it is difficult to maintain a sufficient temperature for mixing or dissolving the polyester resin in this organic compound. When the boiling point is higher than 200 ° C., the drying property of the coating film obtained is insufficient, and the handling is not easy and easy.

Examples of the water-soluble organic compound include:
Methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-
Monohydric alcohols such as butanol and tert-butanol; glycols such as ethylene glycol and propylene glycol; glycol derivatives such as methyl cellosolve, ethyl cellosolve, n-butyl cellosolve, 3-methyl-3-methoxybutanol and n-butyl cellosolve acetate. Dioxane, ethers such as tetrahydrofuran, esters such as ethyl acetate; and ketones such as methyl ethyl ketone, cyclohexanone, cyclooctanone, cyclodecane, isophorone. Preferred are n-butyl cellosolve, ethyl cellosolve, and isopropanol. These water-soluble organic compounds may be used alone or in combination of two or more. When an amide-based or sulfonic acid ester-based compound is used as the water-soluble compound, the storage stability of the water-based resin dispersion is insufficient and the resulting coating film has insufficient dryness.

The above water-soluble organic compound is used as a dispersion mixture 1
It is contained in an amount of 2 to 30 parts by weight, preferably 2 to 25 parts by weight, and more preferably 10 to 20 parts by weight in 00 parts by weight. When the content is less than 2 parts by weight, the dispersibility of the polyester resin and the silicone compound is insufficient. 30
When the amount is more than parts by weight, the drying property of the obtained coating film is insufficient, so that handling is not easy and easy.

The aqueous composite resin dispersion of the present invention is particularly preferably based on 100 parts by weight of the above polyester resin.
0.3-10 parts by weight of the silicone compound, 0.3-3 parts by weight of the surfactant, and 5 parts of the water-soluble organic compound.
It may be prepared to contain 0 parts by weight and 170 to 182 parts by weight of water.

Using each of the above raw materials, the aqueous composite resin dispersion of the present invention can be produced by any of the following methods:
(1) The polyester resin, the silicone compound,
Water is gradually added to and dispersed in a mixture of the above surfactant and the above water-soluble organic compound;
(2) A mixture of the polyester resin, the silicone compound, the surfactant, and the water-soluble organic compound is gradually added to water and dispersed therein; (3) the polyester resin, the silicone compound, the surfactant, The water-soluble organic compound and water are collectively mixed and dispersed.

In any of the above cases (1) to (3), the silicone compound is encapsulated in the polyester resin particles when dispersed in water. That is, the polyester resin particles are encapsulated in a state where the silicone compound is dissolved in the water-soluble organic compound that is the dispersion aid. The methods (1) and (2) are preferable in that a part of the silicone compound is efficiently encapsulated in the polyester resin particles and a more transparent and homogeneous coating film can be obtained.

If necessary, other aqueous resins and / or aqueous additives may be added to the aqueous composite resin dispersion of the present invention as long as the object of the present invention is not impaired.

[0038]

The aqueous composite resin dispersion of the present invention contains the polyester resin having the above-mentioned characteristics, the silicone compound, the surfactant, the water-soluble organic compound and water in the appropriate proportions as described above. Excellent water dispersibility of resin. Further, in this water-based composite resin dispersion, the silicone compound has a part thereof encapsulated in the polyester resin particles, and therefore, does not cause coagulation and precipitation and is excellent in dispersion stability. The coating film obtained from this aqueous composite resin dispersion,
It is transparent and homogeneous, has excellent water resistance and release properties, and is easy and easy to handle.

[0039]

EXAMPLES The present invention will be described in more detail by way of examples, but the present invention is not limited thereto. The evaluation items in the examples of the present invention are as follows. Unless stated otherwise in the examples, parts refer to parts by weight.

Copolymer Composition The copolymer composition ratio of the polyester resin was calculated in mol% from the integrated intensity ratio of ¹ HNMR.

Softening point Fully automatic melting point measuring device (FP-1 made by METTLER)
Was used to measure the melting point of the polyester resin, which was taken as the softening point.

Number Average Molecular Weight The number average molecular weight of the polyester resin was calculated in terms of polystyrene by GPC (CR-SA, manufactured by Shimadzu Corporation).

Average particle size The average particle size of the aqueous resin dispersion was measured using Coulter N4 type (manufactured by Coulter).

Appearance of Coating Film The appearance of the coating film was visually determined and evaluated according to the following criteria. ◯: It is transparent. Δ: Somewhat whitened. X: Whitened.

Water resistance A 125 μm thick polyethylene terephthalate film was coated with a water-based resin dispersion using a bar coater # 20 to a solid film thickness of 10 μm, and dried with hot air at 100 ° C. for 20 minutes to form a coating film. Was formed. The appearance of this coating film was visually determined and evaluated according to the following criteria. ◯: It is transparent. Δ: Somewhat whitened. X: Whitened.

Releasability Aqueous resin dispersion is applied to a polyethylene terephthalate film having a thickness of 125 μm using a bar coater # 20 so that the solid film thickness becomes 10 μm, and dried by hot air drying at 100 ° C. for 20 minutes. A film was formed. The coated surface of the polyethylene terephthalate film having this coating film and the uncoated polyethylene terephthalate film were adhered by pressing at 60 ° C. for 1 minute.
Then, the adhered film was peeled off by a human hand without using an apparatus, and evaluated according to the following criteria. ○: Easy to peel off. Δ: Peeled off but the coating film surface is rough. X: It does not come off at all.

(Production Example 1) In an autoclave equipped with a thermometer and a stirrer, 95 parts of dimethyl terephthalate, 95 parts of dimethyl isophthalate, 6 parts of 5-sodium sulfoisophthalic acid, 71 parts of ethylene glycol, 110 parts of neopentyl glycol. , And 0.3 part of tetrabutoxy titanate were charged and heated at 150 to 220 ° C. for 240 minutes. Then the above reactive mixture is heated to 250 ° C. for 10 minutes.
After that, the temperature was raised to 0.3 mmHg or less in 25 minutes. While maintaining a reduced pressure condition of 0.3 mmHg or less, the above reactive mixture was allowed to stand for another 60 minutes to obtain a pale yellow and transparent polyester A. The obtained polyester A was subjected to the above evaluations 1 to. The results are shown in Table 1.

(Production Examples 2-5) Polyester resin B was prepared in the same manner except that the copolymerization components shown in Table 1 were used.
-E were obtained and used for the above-mentioned evaluations. The results are shown in Table 1.

(Example 1) The above polyester resin A30
0 parts, silicone oil (KS770A, manufactured by Shin-Etsu Chemical)
9 parts, 0.9 parts of nonionic surfactants (YX500, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) and 150 parts of n-butyl cellosolve were charged in a container and stirred at 110 ° C to 130 ° C for about 3 hours to give a uniform and viscous material. A liquid was obtained. The liquid is then cooled,
535 parts of water was gradually added with vigorous stirring at 80-100 ° C. After about 1 hour, a uniform, white aqueous resin dispersion was obtained. The obtained water-based resin dispersion was subjected to the above evaluations 1 to. Table 2 shows the results.

(Example 2) An aqueous resin dispersion was obtained in the same manner as in Example 1 except that the polyester resin B shown in Table 1 was used and subjected to the above-mentioned evaluations. Table 2 shows the results.

Example 3 An aqueous resin dispersion was obtained in the same manner as in Example 1 except that a mixed solvent of n-butyl cellosolve and ethyl cellosolve shown in Table 2 was used as the water-soluble organic compound. The above-mentioned items 1 to 3 were evaluated.
Table 2 shows the results.

(Comparative Example 1) An aqueous resin dispersion was obtained in the same manner as in Example 1 except that the polyester resin C shown in Table 1 was used and subjected to the above-mentioned evaluations. Table 2 shows the results.

(Comparative Example 2) An aqueous resin dispersion was obtained in the same manner as in Example 1 except that the polyester resin D shown in Table 1 was used and subjected to the above-mentioned evaluations. Table 2 shows the results.

(Comparative Example 3) An aqueous resin dispersion was obtained in the same manner as in Example 1 except that the polyester resin E shown in Table 1 was used. Table 2 shows the results.

(Comparative Example 4) An aqueous resin dispersion was obtained in the same manner as in Example 1 except that the silicone compound and the surfactant were not used, and was subjected to the above-mentioned evaluations.
Table 2 shows the results.

(Comparative Example 5) An aqueous resin dispersion was obtained in the same manner as in Example 1 except that a cationic surfactant (acetamine 24, manufactured by Kao) was used as the surfactant. It provided for evaluation. Table 2 shows the results.

(Comparative Example 6) An aqueous resin dispersion was obtained in the same manner as in Example 1 except that the water-soluble organic compound was not used, and was subjected to the above-mentioned evaluations. Table 2 shows the results.

[0058]

[Table 1]

[0059]

[Table 2]

As can be seen from Table 2, the aqueous composite resin dispersion of the present invention is excellent in water dispersibility, and the resulting coating film is excellent in appearance, water resistance and releasability.

[0061]

According to the present invention, as described above, a water-based composite resin dispersion having excellent water dispersibility, which is transparent and homogeneous, has excellent water resistance and release properties, and is easy to handle. There is provided an aqueous composite resin dispersion capable of forming. Thus, the water-based composite resin dispersion of the present invention satisfying a plurality of properties at the same time has various uses, for example, various information recording materials such as a release coating agent for image recording media and a back coating agent for magnetic recording media. It is suitable for use as a coating agent.

Claims (2)

[Claims] 1. A polyester resin in an amount of 10 to 70 parts by weight,
0.1 to 20 parts by weight of a silicone compound, 0.1 to 5 parts by weight of a surfactant, 2 to 30 parts by weight of a water-soluble organic compound, and 20 to 87.8 parts by weight of water,
The total amount of the polyester resin, the silicone compound, the surfactant, the water-soluble organic compound and the water is 1
A water-based composite resin dispersion containing 100 parts by weight, wherein the polyester resin has at least one anionic polar group, and the polyester resin has a softening point of 4
0 to 200 ° C., the number average molecular weight of the polyester resin is 1
500 to 30,000, at least a part of the silicone compound is encapsulated in the particles of the polyester resin, the surfactant is a nonionic surfactant and / or an anionic surfactant, and A water-based composite resin dispersion in which the boiling point of the organic compound is 60 to 200 ° C. 2. The polyester resin is 10 to 50 parts by weight, the silicone compound is 0.1 to 5 parts by weight, the surfactant is 0.1 to 1 part by weight, and the water-soluble organic compound is 2 to 25 parts by weight. Parts and water in a proportion of 19 to 87.8 parts by weight, and the total amount of the polyester resin, the silicone compound, the surfactant, the water-soluble organic compound and the water is 100 parts by weight. The aqueous composite resin dispersion according to claim 1, which is contained in.