JP2005082606A - Aqueous polyamide resin dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous polyamide resin dispersion excellent in both yellowing resistance and storage stability, wherein when the aqueous dispersion adhered to the inner wall of a container is dried during storage or transportation, it does not form a solid matter which is peeled and mixed into the aqueous dispersion. <P>SOLUTION: The aqueous polyamide resin dispersion comprises a polyamide resin, an ammonium compound and a paraffin, dispersed in an aqueous medium. Preferably, the ammonium compound is contained in an amount of 0.01-100 pts. wt. based on 100 pts. wt. of the polyamide resin, and the paraffin is contained in an amount of 0.1-15 pts. wt. based on 100 pts. wt. of the polyamide resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an aqueous polyamide resin dispersion. More specifically, the present invention relates to an aqueous polyamide resin dispersion having excellent yellowing resistance and excellent storage stability.

  Aqueous dispersion of polyamide resin provides oil resistance, solvent resistance, chemical resistance, abrasion resistance, gas barrier property, adhesion, etc. by forming a coating film of polyamide resin on the base material Hot melts such as water-based inks, fiber treatment agents, fiber sealants, glass fiber sizing agents, paper treatment agents, binders, lubricants, steel sheet surface treatment agents, surface modifiers and interlining adhesives Used for adhesives.

  Generally, polyamide resins have a problem that yellowing due to terminal amino groups is likely to occur, and various proposals have conventionally been made as methods for preventing yellowing of polyamide resins. For example, the polyamide resin composition (patent document 1) etc. containing a polyamide resin and an ammonium compound are mentioned.

JP 2001-200196 A

However, this method is excellent in yellowing resistance, but when used in the form of an aqueous dispersion, the aqueous dispersion adhered to the inner wall of the container during storage or transportation is dried to form a solid. Solids may be peeled off and mixed in the aqueous dispersion, leaving room for improvement in storage stability.

  The object of the present invention is excellent in yellowing resistance, and the aqueous dispersion adhered to the inner wall of the container during storage or transportation is dried to become a solid, and the solid does not peel off and mix into the aqueous dispersion. An object is to provide an aqueous polyamide resin dispersion having excellent storage stability.

  That is, the present invention relates to an aqueous polyamide resin dispersion obtained by dispersing a polyamide resin, an ammonium compound and paraffin in an aqueous dispersion medium.

  The aqueous polyamide resin dispersion of the present invention is excellent in yellowing resistance and storage stability, so that it is water-based ink, fiber treatment agent, fiber sealant, glass fiber sizing agent, paper treatment agent, binder, lubrication. It can be used for hot-melt adhesives such as adhesives, steel sheet surface treatment agents, surface modifiers and interlining adhesives.

  As the polyamide resin used in the present invention, one produced by a known method is used. Examples thereof include polyamide resins produced by methods such as polycondensation of diamine and dicarboxylic acid, polycondensation of ω-amino-ω ′ carboxylic acid, and ring-opening polymerization of cyclic lactam. Here, dicarboxylic acid or monocarboxylic acid can be used as a polymerization regulator in the polycondensation or ring-opening polymerization.

  Specific examples of the diamine used in the production of the polyamide resin include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9. -Diaminononane, 1,10-diaminodecane, phenylenediamine, metaxylylenediamine and the like.

  Specific examples of the dicarboxylic acid used for producing the polyamide resin include glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, tetradecanedicarboxylic acid, octadecanedicarboxylic acid, fumaric acid, Examples thereof include phthalic acid, xylylene dicarboxylic acid and dimer acid (unsaturated dicarboxylic acid having 36 carbon atoms synthesized from unsaturated fatty acid mainly composed of linoleic acid or oleic acid).

  Specific examples of the ω-amino-ω′-carboxylic acid used in the production of the polyamide resin include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid. Etc.

  Specific examples of the cyclic lactam used for the production of the polyamide resin include ε-caprolactam, ω-enantolactam, and ω-lauryl lactam.

  Specific examples of the dicarboxylic acid used as the polymerization regulator include glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decane, as well as the dicarboxylic acid used in the production of the polyamide resin. Examples include dicarboxylic acid, tetradecanedicarboxylic acid, octadecanedicarboxylic acid, fumaric acid, phthalic acid, xylylene dicarboxylic acid, and dimer acid. Specific examples of the monocarboxylic acid include caproic acid, heptanoic acid, nonanoic acid, undecanoic acid, and dodecanoic acid.

In the present invention, among the polyamide resins obtained by the above method, in particular, — [NH (CH ₂ ) ₅ CO] —, — [NH (CH ₂ ) ₆ NHCO (CH ₂ ) ₄ CO] —, — [NH _{(CH 2) 6 NHCO (CH} 2) 8 CO] -, - [NH (CH 2) 10 CO] -, - [NH (CH 2) 11 CO] - and _{- [NH (CH 2) 2} NHCO-D A polyamide resin having at least one selected from the group consisting of —CO] — (wherein D represents an unsaturated hydrocarbon having 34 carbon atoms) as a structural unit is preferably used.

  Specific examples thereof include 6-nylon, 66-nylon, 610-nylon, 11-nylon, 12-nylon, 6/66 copolymer nylon, 6/610 copolymer nylon, 6/11 copolymer nylon, 6 / 12 copolymer nylon, 6/66/11 copolymer nylon, 6/66/12 copolymer nylon, 6/66/11/12 copolymer nylon, 6/66/610/11/12 copolymer nylon and dimer acid system Polyamide resin etc. are mentioned. These polymers or copolymers may be used alone or as a mixture of two or more.

  Although it does not specifically limit as an ammonium compound used for this invention, For example, ammonium salt of sulfate ester, ammonium salt of carboxylic acid, ammonium salt of sulfonic acid, ammonium salt of phosphate ester, inorganic ammonium salt, etc. are mentioned.

  Specific examples of the ammonium salt of the sulfate ester include alkyl sulfate ammonium salts such as ammonium lauryl sulfate, ammonium oleyl sulfate, ammonium 2-ethylhexyl sulfate and ammonium isostearyl sulfate; ammonium sulfate salts such as funnel oil ammonium salt and Turkish red oil ammonium salt; Polyoxyethylene alkyl ether ammonium sulfates such as polyoxyethylene lauryl ether ammonium sulfate and polyoxyethylene isostearyl ether ammonium sulfate; Polyoxyethylene alkyl phenyl ether ammonium sulfates such as polyoxyethylene nonyl phenyl ether ammonium sulfate; Mono fatty acids such as glyceryl ammonium monolaurate Ammonium glyceryl sulfate; and lauryl eta Fatty acid alkylol amide sulfate such as Ruamaido ammonium sulfate.

  Specific examples of the ammonium salt of the carboxylic acid include fatty acid ammonium salts such as ammonium laurate, ammonium oleate, and ammonium stearate; polyoxyethylene alkyl ether carboxylic acid ammonium salts such as polyoxyethylene lauryl ether ammonium acetate; N- N-acylamino acid ammonium salts such as lauroyl-N-methyl-β-alanine ammonium, N-lauroyl-N-methylglycine ammonium; ethylene / acrylic acid copolymer ammonium salt, ethylene / methacrylic acid copolymer ammonium salt, etc. Ethylene / α, β-unsaturated carboxylic acid copolymer ammonium salt; other styrene / maleic anhydride copolymer ammonium salt, isobutylene / maleic anhydride copolymer ammonium salt, polyacryl Ammonium salts, acrylic acid / acrylic ester copolymer ammonium salt, carboxymethyl cellulose ammonium salt, alginic acid ammonium salt, and methyl vinyl ether-maleic anhydride ammonium salt and the like.

  Specific examples of the ammonium salt of sulfonic acid include alkylbenzene sulfonic acid ammonium salt such as ammonium dodecylbenzene sulfonate; alkyl naphthalene sulfonic acid ammonium salt such as ammonium diisopropylnaphthalene sulfonate; formalin condensate of ammonium naphthalene sulfonate, melamine sulfone Formalin condensate of ammonium sulfonate such as formalin condensate of ammonium sulfate; ammonium dialkylsulfosuccinate such as ammonium di-2-ethylhexyl sulfosuccinate and ammonium dilauryl sulfosuccinate; ammonium salt of alkyl sulfoacetate such as ammonium lauryl sulfoacetate Α-olefin sulfonic acid ammonium salts such as ammonium tetradecene sulfonate; and N— Uril N- acylmethyltaurine ammonium salts such as methyl taurine ammonium.

  Specific examples of the ammonium salt of phosphate ester include alkyl ether phosphate ammonium salts such as lauryl ether phosphate ammonium; and alkyl phosphate ammonium salts such as lauryl phosphate ammonium.

  Examples of the inorganic ammonium salt include ammonium sulfate, ammonium acetate, ammonium hydrogen carbonate, urea, ammonium chloride, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, and ammonia.

  Of the ammonium compounds, ammonium sulfate salts are preferably used. As the ammonium salt of the sulfate ester, an alkyl sulfate ammonium salt such as ammonium lauryl sulfate is preferably used, and a polyoxyethylene alkyl ether ammonium sulfate salt such as polyoxyethylene lauryl ether ammonium sulfate is preferably used.

  Furthermore, among the ammonium compounds, ammonium salts of carboxylic acids are preferably used. As the carboxylic acid ammonium salt, an ethylene / α, β-unsaturated carboxylic acid copolymer ammonium salt, for example, an ethylene / acrylic acid copolymer ammonium salt is more preferably used. In addition, you may use an above described ammonium compound individually or in mixture of 2 or more types.

  The amount of the ammonium compound used is 0.01 to 100 parts by weight, preferably 0.1 to 50 parts by weight, based on 100 parts by weight of the polyamide resin. When the usage-amount of an ammonium compound is less than 0.01 weight part, there exists a possibility that the effect sufficient for yellowing resistance may not be seen. Moreover, when the usage-amount of an ammonium compound exceeds 100 weight part, there exists a possibility of inhibiting the original performance of a polyamide resin.

  Although it does not specifically limit as paraffin used for this invention, For example, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, and liquid paraffin Etc.

  Among the paraffins, n-tetradecane, n-pentadecane, n-hexadecane and liquid paraffin are particularly preferably used. These paraffins may be used alone or in admixture of two or more.

  The amount of the paraffin used is 0.1 to 15 parts by weight, preferably 0.5 to 12 parts by weight with respect to 100 parts by weight of the polyamide resin. If the amount of paraffin used is less than 0.1 parts by weight, there is a risk that sufficient effect on the storage stability of the aqueous polyamide resin dispersion may not be observed. Moreover, when the usage-amount of paraffin exceeds 15 weight part, there exists a possibility of inhibiting the original performance of a polyamide resin.

  The manufacturing method of the polyamide resin aqueous dispersion of the present invention is not particularly limited, and can be manufactured by a known method. For example, (1) a method of dispersing a polyamide resin powder obtained by pulverizing a polyamide resin by a mechanical pulverization method, a freeze pulverization method, or a wet pulverization method, an ammonia compound, and paraffin in an aqueous dispersion medium, and (2) a polyamide resin. An aqueous dispersion obtained by forcibly dispersing by heating, at a temperature above the softening point of the polyamide resin, in an aqueous dispersion medium in which a basic substance and, if necessary, a surfactant, a dispersing agent, etc. are dissolved under heating And a method of adding and dispersing an aqueous solution of an ammonium compound and paraffin.

  The basic substance is not particularly limited, and examples thereof include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, ammonia, and amine compounds. Among these, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferably used in terms of dispersion effect.

  The aqueous dispersion medium used in the production method is generally ordinary tap water or deionized water. For example, for the purpose of further improving the stability of the aqueous dispersion medium, polyglycerin fatty acid ester, polyvinyl alcohol, polyacrylic acid is used. Water having a viscosity adjusted by adding a water-soluble resin such as sodium acid, carboxymethyl cellulose, or hydroxyethyl cellulose may be used.

  The amount of the aqueous dispersion medium used is usually 30 to 1500 parts by weight, preferably 50 to 500 parts by weight with respect to 100 parts by weight of the polyamide resin. When the amount of the aqueous dispersion medium used is less than 30 parts by weight, the polyamide resin may not be sufficiently dispersed in water. Moreover, when the usage-amount of an aqueous dispersion medium exceeds 1500 weight part, the density | concentration of the obtained dispersion liquid will become thin and it is unpreferable on use.

  The weight average particle diameter of the particles in the polyamide resin aqueous dispersion obtained by the production method is preferably 0.1 to 1000 μm, more preferably 0.1 to 500 μm. The resin concentration in the aqueous dispersion is preferably 1 to 70% by weight.

  The aqueous polyamide resin dispersion of the present invention may contain an antifoaming agent, a viscosity modifier, an antifungal agent and the like as long as the object of the present invention is not impaired. If necessary, an antioxidant, a fatty acid amide, a wax, a slipping improver such as silicone oil, a surfactant, and the like may be blended.

  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.

Example 1
A 500 ml beaker equipped with a magnetic stirrer was charged with 60 g of polyamide resin powder (6/66/12 copolymer nylon, weight average particle size 200 μm), 1 g of polyoxyethylene nonylphenyl ether and 59 g of water, and a rotational speed of 500 rpm. For 30 minutes to obtain an aqueous dispersion. The resin concentration of the obtained aqueous dispersion was 50% by weight.

  A 500 ml beaker equipped with a magnetic stirrer was charged with 50 g of the aqueous dispersion obtained by the above method, 4 g of a 25 wt% aqueous solution of ammonium lauryl sulfate and 0.5 g of n-tetradecane, and stirred at a rotation speed of 500 rpm for 30 minutes. Thus, an aqueous polyamide resin dispersion of the present invention was obtained.

Example 2
In Example 1, an aqueous polyamide resin dispersion of the present invention was obtained in the same manner as in Example 1 except that 1 g of n-pentadecane was used instead of 0.5 g of n-tetradecane.

Example 3
In Example 1, an aqueous polyamide resin dispersion of the present invention was obtained in the same manner as in Example 1 except that 1 g of n-hexadecane was used instead of 0.5 g of n-tetradecane.

Example 4
In Example 1, an aqueous polyamide resin dispersion of the present invention was obtained in the same manner as in Example 1 except that 2 g of liquid paraffin was used instead of 0.5 g of n-tetradecane.

Example 5
A pressure-resistant autoclave (with a heating jacket) having an inner diameter of 110 mm, a height of 250 mm and an internal volume of 1.5 L equipped with a turbine-type stirring blade having a diameter of 50 mm, 120 g of polyamide resin (6/66/12 copolymer nylon), water 179. 6 g and 0.4 g of sodium hydroxide were charged and sealed. The inside of the autoclave was heated up to 150 ° C. by starting the stirrer and circulating heating oil through the jacket while stirring at a rotation speed of 500 rpm. The mixture was stirred for 30 minutes while maintaining the internal temperature at 150 ° C., then cooled to 50 ° C., and the aqueous dispersion was taken out from the autoclave. The resin concentration of the obtained aqueous dispersion was 40% by weight, and the weight average particle size was 0.6 μm as measured by a laser diffraction particle size distribution analyzer (SALD2000 manufactured by Shimadzu Corporation).

  A 500 ml beaker equipped with a magnetic stirrer was charged with 75 g of the aqueous dispersion obtained by the above method, separately prepared 3 g of 25 wt% ammonium lauryl sulfate aqueous solution, and 0.2 g of n-tetradecane, and rotated at 500 rpm. The mixture was stirred and dispersed for 30 minutes to obtain an aqueous polyamide resin dispersion of the present invention.

Example 6
In Example 5, an aqueous polyamide resin dispersion of the present invention was obtained in the same manner as in Example 5 except that 2 g of n-pentadecane was used instead of 0.2 g of n-tetradecane.

Example 7
In Example 5, an aqueous polyamide resin dispersion of the present invention was obtained in the same manner as in Example 5 except that 3 g of n-hexadecane was used instead of 0.2 g of n-tetradecane.

Example 8
In Example 5, an aqueous polyamide resin dispersion of the present invention was obtained in the same manner as in Example 5 except that 2 g of liquid paraffin was used instead of 0.2 g of n-tetradecane.

Comparative Example 1
In Example 1, an aqueous polyamide resin dispersion was obtained in the same manner as in Example 1 except that 0.5 g of n-tetradecane was not used.

Comparative Example 2
In Example 5, an aqueous polyamide resin dispersion was obtained in the same manner as in Example 5 except that 0.2 g of n-tetradecane was not used.

  The yellowing resistance and storage stability of the polyamide resin aqueous dispersions obtained in Examples 1 to 8 and Comparative Examples 1 and 2 were evaluated by the following methods. The results are shown in Table 1.

Yellowing-resistant cotton cloth (approx. 3 × 5 cm) coated with an aqueous polyamide resin dispersion was heat-dried at 100 ° C. for 2 hours to obtain a cotton cloth treated with polyamide resin. The obtained cotton cloth and IMPREGNATED TEST PAPER (Yellowing Test Kit: James H. Heal & Co. Ltd) were overlapped and sandwiched between two slide glasses. After surrounding the slide glass with aluminum foil, it was placed in a dryer set at 60 ° C. for 3 hours. The color difference (L, a, b) of the obtained cotton cloth was obtained by a reflection method using a colorimetric color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., Z-1001DP type), and the whiteness was obtained from the following formula.
Whiteness = 100 − ((100−L) ² + a ² + b ² ) ^1/2
Usually, when the whiteness is 90 or more, it can be judged that the yellowing resistance is excellent.

Storage stability A polyethylene sheet (2 cm × 10 cm × 0.3 cm) cut into strips was immersed in an aqueous polyamide resin dispersion and slowly pulled up. Then, the adhesion state of the aqueous dispersion of the immersed part was observed visually, and evaluation was performed as follows.
○: Aqueous dispersion adheres to 30% or less of the area of the soaked portion, and after standing for 1 hour, no solid matter is formed when the attached aqueous dispersion is dried.
Δ: An aqueous dispersion adheres to 30 to 70% of the area of the immersed part, and after standing for 1 hour, a solid matter is slightly formed when the attached aqueous dispersion is dried.
X: An aqueous dispersion adheres to 70% or more of the area of the immersed part, and after standing for 1 hour, solid matter is generated when the attached aqueous dispersion is dried.

As shown in Table 1, it can be seen that the aqueous polyamide resin dispersions of Examples 1 to 8 are excellent in yellowing resistance and excellent in storage stability. On the other hand, it can be seen that the aqueous polyamide resin dispersions of Comparative Examples 1 and 2 are excellent in yellowing resistance but inferior in storage stability.

Claims (6)

  An aqueous polyamide resin dispersion comprising a polyamide resin, an ammonium compound and paraffin dispersed in an aqueous dispersion medium.   The aqueous polyamide resin dispersion according to claim 1, wherein the amount of the ammonium compound is 0.01 to 100 parts by weight with respect to 100 parts by weight of the polyamide resin.   The aqueous polyamide resin dispersion according to claim 1 or 2, wherein the amount of paraffin is 0.1 to 15 parts by weight with respect to 100 parts by weight of the polyamide resin. Polyamide _{resin, - [NH (CH 2)} 5 CO] -, - [NH (CH 2) 6 NHCO (CH 2) 4 CO] -, - [NH (CH 2) 6 NHCO (CH 2) 8 CO] -,-[NH (CH ₂ ) ₁₀ CO]-,-[NH (CH ₂ ) ₁₁ CO]-and-[NH (CH ₂ ) ₂ NHCO-D-CO]-(wherein D has 34 carbon atoms) The aqueous polyamide resin dispersion according to any one of claims 1 to 3, wherein at least one selected from the group consisting of unsaturated hydrocarbons) is a structural unit.   The ammonium compound is at least one selected from the group consisting of an ammonium salt of a sulfate ester, an ammonium salt of a carboxylic acid, an ammonium salt of a sulfonic acid, an ammonium salt of a phosphate ester, and an inorganic ammonium salt. The aqueous dispersion of polyamide resin according to claim 1. The aqueous polyamide resin dispersion according to any one of claims 1 to 5, wherein the paraffin is at least one selected from the group consisting of n-tetradecane, n-pentadecane, n-hexadecane and liquid paraffin.