JP2003082282A - Aqueous anchor coating agent - Google Patents

Abstract

(57) [Problem] To provide an aqueous anchor coating agent for extrusion lamination, which can be easily dispersed in water and has a long pot life of an aqueous dispersion. SOLUTION: At least the following polyisocyanates (A) and (B) are mass ratio (A) :( B) = 10 /.
The problem is solved by an aqueous anchor coating agent contained in a ratio of 90 to 90/10. In addition, in obtaining (B), it is preferable to use a zirconium carboxylate as a catalyst. (A): a polyisocyanate obtained by reacting an isocyanurate-modified polyisocyanate of hexamethylene diisocyanate (A1) with an adduct (A2) of at least a monool alkylene oxide (containing at least 30 mol% of ethylene oxide). (B): average number of functional groups is 2 to 3, viscosity at 25 ° C is 50
Allophanate group-containing polyisocyanate of 0 mPa · s or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous anchor coating agent used in extrusion laminating.

[0002]

2. Description of the Related Art In the field of extrusion lamination, it is known that a laminate film excellent in water resistance and boil resistance can be obtained by using a polyisocyanate (urethane) anchor coating agent. The conventional polyisocyanate-based (urethane-based) anchor coating agent is mainly of a type dissolved in an organic solvent. (JP-A-2-
63060 publication)

On the other hand, as a water-based anchor coating agent having a higher environmental suitability than that of an organic solvent type, a polybutadiene type,
Examples include imine series. However, these anchor coating agents are insufficient in water resistance and boil resistance. For this reason, studies have been conducted on anchor coating agents of aqueous polyisocyanate (urethane type).

However, the conventional aqueous polyisocyanate has a problem that when it is dispersed in water, the isocyanate group is reduced by the reaction between the isocyanate group and water, and a sufficient pot life (pot life) cannot be secured. For this reason, the work efficiency is poor, and the residual liquid mixture is lost.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous anchor coating agent for extrusion laminating, which can be easily dispersed in water and has a long pot life of the aqueous dispersion.

[0006]

As a result of intensive studies, the present inventors have found that an aqueous anchor coating agent obtained by mixing a specific polyisocyanate solves the above problems, and complete the present invention. Came to. That is, the present invention is shown in the following (1) to (3). (1) At least the following polyisocyanates (A) and (B) in mass ratio (A) :( B) = 10/9
An aqueous anchor coating agent contained in a ratio of 0 to 90/10. (A): A polyisocyanate obtained by reacting an isocyanurate-modified polyisocyanate (A1) of hexamethylene diisocyanate with an alkylene oxide adduct (A2) containing at least a monool (containing at least 30 mol% of ethylene oxide). (B): The average number of functional groups is 2 to 3, and the viscosity at 25 ° C. is 50.
Polyisocyanates containing allophanate groups of 0 mPa · s or less.

(2) The aqueous anchor coat agent according to (1) above, wherein (B) is obtained by reacting hexamethylene diisocyanate with an alcohol in the presence of a carboxylic acid zirconium salt.

(3) The aqueous anchor coating agent according to the above (1) or (2), which further contains an aqueous resin containing an alcoholic hydroxyl group.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Raw materials used in the present invention will be described. The polyisocyanate (A) used in the present invention contains at least hexamethylene diisocyanate (hereinafter abbreviated as HDI) isocyanurate-modified polyisocyanate (A1) and monool alkylene oxide (provided that 30 mol% or more of ethylene oxide is contained. ) It consists of an adduct (A2). In addition, in this invention, (A) is called hydrophilic polyisocyanate.

(A1) is an HDI isocyanurate-modified polyisocyanate having an isocyanate group and an isocyanurate group in the molecule. In addition, (A
1) may have a urethane group, a urea group, or the like.

(A1) is based on HDI
This is because the weather resistance and the reactivity between the isocyanate group and water when dispersed in water are taken into consideration. In addition, a part of HDI can be replaced with other organic diisocyanate as long as weather resistance and the like are not significantly impaired.

(A1) is obtained by a known method, and specifically, it is obtained by the following method. (A): An isocyanurate-forming catalyst is added to HDI to perform an isocyanurate-forming reaction, and the isocyanurate-forming reaction is stopped by adding a catalyst poison, and then free HDI is removed. (B): HDI is reacted with a polyol to carry out a urethanization reaction to synthesize an isocyanate group-terminated prepolymer, an isocyanurate-forming catalyst is added to this to carry out an isocyanurate-forming reaction, and a catalyst poison is added to form an isocyanurate. After stopping the reaction, free HDI is removed.

In the case of (b), the initial charging ratio of HDI and polyol is "amount in which the isocyanate group is in excess of the hydroxyl group", and the molar ratio of the isocyanate group and the hydroxyl group is isocyanate group / hydroxyl group = 8 or more. Is preferred,
10 to 50 is particularly preferable.

As the isocyanurate-forming catalyst, known catalysts can be used, for example, tetraalkylammonium hydroxide such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, tetramethylammonium acetate salt, Organic weak acid salts such as tetraethylammonium acetate and tetrabutylammonium acetate, trimethylhydroxypropylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, triethylhydroxypropylammonium hydroxide, trialkylhydroxykilammonium salts such as triethylhydroxyethylammonium hydroxide Hydroxide, vinegar Trimethyl hydroxypropyl ammonium salts, acetate trimethyl hydroxyethyl ammonium salts, triethylammonium acetate hydroxypropyl ammonium salts, organic weak acid salt, such as triethylammonium acetate hydroxyethyl ammonium salts, triethylamine, tertiary amines such as triethylenediamine, acid, caproic acid, octyl acid,
Examples thereof include metal salts of alkylcarboxylic acids such as myristic acid.

As a catalyst poison for the isocyanurate-forming reaction, inorganic acids such as phosphoric acid and hydrochloric acid, organic acids having sulfonic acid, sulfamic acid groups and the like, and esters thereof,
Examples thereof include acyl halides.

As the polyol in (b), ethylene glycol, 1,2-propanediol, 1,3-
Propanediol, 1,2-butanediol, 1,3-
Butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2-ethyl-2-n-butyl-1. , 3-propanediol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, or ethylene oxide or propylene oxide adduct of bisphenol A, trimethylolpropane, Low molecular weight polyols having a number average molecular weight of 500 or less, such as glycerin and pentaerythritol, succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid Hexahydrophthalic ortho-phthalic acid,
In the reaction of one or more kinds of polycarboxylic acids such as naphthalenedicarboxylic acid and trimellitic acid, acid esters, or acid anhydrides with one or more kinds of the above-mentioned low-molecular polyols, low-molecular polyamines and low-molecular amino alcohols. Polyester polyols and polyester amide polyols obtained,
In addition, low molecular weight polyol, low molecular weight polyamine, low molecular weight amino alcohol as an initiator, ε-caprolactone,
Lactone-based polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as γ-valerolactone, a dealcoholation reaction of the aforementioned low molecular weight polyol with diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, etc.,
Polycarbonate polyols obtained by dephenolization reaction, low molecular weight polyols used in the above polyester polyols, low molecular weight polyamines, low molecular weight amino alcohols as initiators, polyethylenes obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc. Glycol, polypropylene glycol,
Polytetramethylene ether glycol and the like, and polyether polyols obtained by copolymerizing these, the polyester polyols described above, polyester ether polyols having a polycarbonate polyol as an initiator, polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, Examples thereof include polyolefin polyols such as hydrogenated polyisoprene, chlorinated polypropylene, and chlorinated polyethylene, castor oil-based polyols, animal and plant-based polyols such as silk fibroin, and the like. You may use these individually or in mixture of 2 or more types. In the present invention, low molecular weight polyols are preferable.

The reaction conditions for the urethane formation in (b) are preferably temperature: 30 to 100 ° C., time: 1 to 10 hours, more preferably 40 to 90 ° C., 1 to 5 hours. In this reaction, a known urethane-forming catalyst such as dibutyltin dilaurate or triethylenediamine can be used. The reaction conditions can be applied to the reaction conditions (A1) and (A2) described later.

The reaction conditions for the isocyanurate formation are as follows:
Amount of catalyst added: 10 to 10,000 pp relative to the reaction system
m, temperature: 0 to 120 ° C., time: 5 to 20 hours, catalyst addition amount: 100 to 5,000 p with respect to the reaction system
pm, temperature: 30 to 70 ° C., time: 8 to 150 hours are more preferable. Further, if the isocyanurate-forming reaction proceeds too much, gelation tends to occur, so that a desired shape cannot be obtained.

The isocyanurate-forming reaction is stopped by adding a catalyst poison. The amount of catalyst poison added is preferably 0.5 to 2 equivalents relative to the isocyanurate-forming catalyst,
0.7 to 1.5 equivalents are particularly preferred.

Incidentally, an organic solvent can be used, if necessary, in the urethanization reaction or isocyanurate reaction. Examples of the organic solvent include aliphatic hydrocarbon-based organic solvents such as n-hexane and octane, alicyclic hydrocarbon-based organic solvents such as cyclohexane and methylcyclohexane, and ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Solvents, ester organic solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate,
3-methyl-3-methoxybutyl acetate, ethyl-
Glycol ether ester organic solvent such as 3-ethoxypropionate, ether organic solvent such as diethyl ether, tetrahydrofuran, dioxane, methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, methylene iodide, dichloroethane, etc. And a polar aprotic solvent such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, and hexamethylphosphonylamide. The solvent is one or two
More than one species can be used.

As a method for removing the free HDI, known methods such as distillation, reprecipitation and extraction can be mentioned. Distillation, especially thin film distillation, can be carried out without using a solvent and the like, and is preferable. In addition, preferable conditions for thin film distillation are: pressure: 0.1 k
Pa or less, temperature: 100 to 200 ° C., particularly preferable conditions are pressure: 0.05 kPa or less, temperature: 120 to 1
It is 80 ° C.

The thus-obtained (A1) has an isocyanate content of 10 to 30% by mass and a viscosity at 25 ° C. of 1,000 to 5,000 mPa · s, preferably 15 to 25% by mass. %, The viscosity at 25 ° C. is 1,500 to 3,500 mPa · s.

(A2) is an alkylene oxide adduct of monool (provided that ethylene oxide is contained in an amount of 30 mol% or more). When the content of ethylene oxide in the alkylene oxide is less than 30 mol%, (A)
The water dispersibility of is likely to be insufficient.

As monools, methanol, ethanol, n-propanol, i-propanol, n-butanol, s-butanol, t-butanol, pentanol, hexanol, heptanol, octanol, 2-
Aliphatic monools such as ethyl-hexanol, benzyl alcohol, methylbenzyl alcohol, capryl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, cinnamyl alcohol, etc. Examples thereof include aromatic monools such as phenols and cresols, and araliphatic monools such as benzyl alcohol. In the present invention, an aliphatic alcohol having 1 to 5 carbon atoms is preferable.

The number average molecular weight of (A2) is 300 to 3,
000 is preferable, and 500 to 2,000 is particularly preferable. When the number average molecular weight is less than 300, the water dispersibility of (A) tends to be insufficient. When it exceeds 3,000, the viscosity of (A) becomes high, and the workability is likely to deteriorate.

(A) is obtained by reacting (A1) with (A2). As the reaction conditions, the urethanization reaction in the above (b) can be applied. (A1) in (A)
The content is preferably 2 to 20% by mass, and particularly preferably 3 to 18% by mass. At this time, a part of (A2) can be replaced with a hydrophobic monol. Examples of the hydrophobic monool include monools, hydroxycarboxylic acids and esters thereof used for obtaining the above-mentioned (A1).

The isocyanate content of the thus obtained (A) is 10 to 30% by mass, and the viscosity at 25 ° C. is 1,0.
0 to 5,000 mPa · s, a preferable isocyanate content is 15 to 25% by mass, and a viscosity at 25 ° C. is 1,5.
It is 00-3,500 mPa * s.

The polyisocyanate (B) is an allophanate group-containing polyisocyanate having an average number of functional groups of 2 to 3 and a viscosity at 25 ° C. of 500 mPa · s or less. When the average number of functional groups is less than the lower limit, the cross-linking efficiency of polyisocyanate is lowered, and the adhesive strength is apt to be lowered. If the upper limit is exceeded, the viscosity of (B) at 25 ° C will be 500 mPa · s.
It is difficult to obtain the following. If the viscosity at 25 ° C exceeds the upper limit, the viscosity of the polyisocyanate obtained will be high, and the workability will tend to be reduced. In addition, in this invention, (B) is called a hydrophobic polyisocyanate.

The method for producing (B) is not particularly limited, and it can be obtained by reacting HDI with an alcohol in the presence of an allophanate-forming catalyst. Here, alcohol is
It means a compound containing an alcoholic hydroxyl group, and does not include a compound such as phenol in which a hydroxyl group is directly bonded to an aromatic ring.

Examples of alcohols include the polyols and monools used in (A) above. These may be used alone or in combination of two or more. In the present invention,
Aliphatic monool (alkyl monool) is preferable,
An aliphatic monool having 1 to 5 carbon atoms (alkyl monool) is particularly preferable.

As the allophanatization catalyst, known catalysts can be used. However, it is preferable to use zirconium carboxylic acid salt because a side reaction such as dimerization or trimerization of an isocyanate group hardly occurs and a low viscosity polyisocyanate is obtained. Further, by using the zirconium carboxylic acid salt, an allophanate-modified polyisocyanate substantially free from coloration can be obtained relatively easily without using a cocatalyst or the like.

As the carboxylic acid, acetic acid, propionic acid, butyric acid, caproic acid, octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, saturated aliphatic carboxylic acid such as 2-ethylhexanoic acid, cyclohexanecarboxylic acid, Saturated monocyclic carboxylic acids such as cyclopentanecarboxylic acid, saturated multicyclic carboxylic acids such as bicyclo (4.4.0) decane-2-carboxylic acid, mixtures of the above carboxylic acids such as naphthenic acid, oleic acid, linoleic acid Unsaturated carboxylic acids such as linolenic acid, soybean oil fatty acid and tall oil fatty acid, araliphatic carboxylic acids such as diphenylacetic acid,
Benzoic acid, monocarboxylic acids such as aromatic carboxylic acids such as toluic acid, phthalic acid, isophthalic acid, terephthalic acid,
Naphthalene dicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid,
Suberic acid, curtaconic acid, azelaic acid, sebacic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydromuconic acid, α-butyl-α-
Examples thereof include polycarboxylic acids such as ethyl glutaric acid, α, β-diethylsuccinic acid, maleic acid, fumaric acid, trimellitic acid and pyromellitic acid. These zirconium carboxylic acid salts may be used alone or in the form of a mixture of two or more kinds. The allophanate-forming catalyst preferred in the present invention is a monocarboxylic acid zirconium salt having 10 or less carbon atoms.

(B) is obtained by a known method, and specifically, it is obtained by the following method. (C): An organic diisocyanate is reacted with an alcohol to carry out a urethanization reaction to synthesize an isocyanate group-terminated prepolymer, an allophanate-forming catalyst is added to this to carry out an allophanate-forming reaction, and an allophanate-forming reaction is carried out by adding a catalyst poison. After stopping, the free organic diisocyanate is removed. (D): The organic diisocyanate and alcohol are subjected to the urethanization reaction and the allophanation reaction in parallel in the presence of the allophanatization catalyst, and the free organic diisocyanate is removed after the allophanatization reaction is stopped by adding the catalyst poison.

Examples of the organic diisocyanate used in (B) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,4'-diphenylmethane diisocyanate. 2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, tetramethyl Xylylene diisocyanate, 4,
4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2 '
-Diphenylpropane-4,4'-diisocyanate,
3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, 3,3'-dimethoxydiphenyl-4,4 '
An aromatic diisocyanate such as diisocyanate, an aliphatic diisocyanate such as tetramethylene diisocyanate, HDI, isophorone diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, lysine diisocyanate, etc. Alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tetramethylxylylene diisocyanate, and cyclohexyl diisocyanate. In the present invention, HDI is preferred because it tends to have a low viscosity (B).

The initial charge ratio of the organic diisocyanate and alcohol is "the amount in which the isocyanate group is in excess of the hydroxyl group", and the molar ratio of the isocyanate group and the hydroxyl group is preferably isocyanate group / hydroxyl group = 8 or more, 10 to 50 is particularly preferable.

Examples of catalyst poisons for the allophanatization reaction include known substances such as inorganic acids such as phosphoric acid and hydrochloric acid, organic acids having a sulfonic acid group, a sulfamic acid group and the like, their esters, and acyl halides.

The conditions for the urethanization reaction in (c) are as follows:
The above-mentioned urethanization reaction conditions can be applied.

The conditions for the urethanization reaction in (c) and the conditions for the urethanization / allophanate reaction in (d) are such that the reaction temperature is 70 to 150 ° C., preferably 80 to
Perform at 130 ° C. If the reaction temperature is too low, allophanate groups will not be formed so much, and the average number of functional groups of the polyisocyanate obtained will decrease. When such a polyisocyanate is used as an anchor coating agent,
Adhesive strength tends to be insufficient. If the reaction temperature is too high, the resulting polyisocyanate is unnecessarily heated, which may cause the polyisocyanate to be colored. The reaction time varies depending on the type and amount of catalyst added and the reaction temperature, but is usually preferably 10 hours or less, and particularly preferably 1 to 5 hours.

The amount of the allophanatization catalyst used varies depending on its type, but is preferably 0.0005 to 1% by mass, more preferably 0.001 to 0.1% by mass, based on the total amount of the organic diisocyanate and alcohol. . When the amount of the catalyst used is less than 0.0005% by mass, the reaction is substantially delayed and it takes a long time, and coloring due to heat history may occur. On the other hand, when the amount of the catalyst used exceeds 1% by mass, it becomes difficult to control the reaction, and a side reaction such as a dimerization reaction (uretdione formation reaction) or a trimerization reaction (isocyanurate formation reaction) easily occurs and the viscosity tends to be high. .

In addition, an organic solvent can be used, if necessary, in the urethanization reaction, allophanate formation reaction, and urethane formation / allophanate formation reaction. Examples of the organic solvent include those mentioned above.

After the allophanatization reaction, a catalyst poison is added to stop the allophanatization reaction. The timing of addition of the catalyst poison is not particularly limited as long as it is after the allophanate-forming reaction, but when the thin film distillation method is used for the method of removing the free organic diisocyanate later, the catalyst is added after the allophanate reaction and before the thin film distillation. It is preferable to add a poison.
This is to prevent side reactions from occurring due to heat during thin film distillation.

The amount of the catalyst poison added varies depending on the type and type of catalyst, but is preferably 0.5 to 2 equivalents of the catalyst, and particularly preferably 0.8 to 1.5 equivalents. If the catalyst poison is too small, the storage stability of the resulting polyisocyanate tends to decrease. If too much, the resulting polyisocyanate may be colored.

Next is a step of removing the free organic diisocyanate. In the present invention, basically, a free organic diisocyanate is present in the product after the allophanatization reaction. This free organic diisocyanate causes odor and turbidity over time. It is preferable to remove the unreacted organic diisocyanate until the amount of free organic diisocyanate is 1% by mass or less, since problems such as odor hardly occur.

As a method for removing the free organic diisocyanate, known methods such as distillation, reprecipitation and extraction can be mentioned. Distillation, particularly thin film distillation can be carried out without using a solvent or the like, and is preferable. In addition, as preferable conditions for thin film distillation, pressure: 0.1 kPa or less, temperature: 100 to 200 ° C.
And particularly preferable conditions are pressure: 0.05 kPa or less and temperature: 120 to 180 ° C.

The viscosity of the thus obtained (B) at 25 ° C. is 500 mPa · s or less, preferably 30
It is 0 mPa · s or less. If the viscosity is too high, the viscosity of the polyisocyanate obtained will be high and the water dispersion operation will be difficult. The isocyanate content is preferably 3 to 25% by mass, more preferably 5 to 23% by mass.

(B) does not have water dispersibility by itself. On the other hand, (A) has water dispersibility, but the pot life when (A) alone is dispersed in water is about 5 to 6 hours. However, the polyisocyanate composition of the present invention contains (A) and (B) in a mass ratio of 10/9.
It was found that the mixture was 0 to 90/10, preferably 40/60 to 90/10, but it was easily dispersed in water and had a pot life of 7 hours or more. If (A) is too much, the pot life will not be extended. If the amount of (B) is too large, precipitation will occur after dispersion in water.

The preferred isocyanate content of the aqueous anchor coating agent of the present invention is 5 to 30% by mass, particularly preferably 10 to 25% by mass. Also, preferably 25 ℃
The viscosity is 200 to 4,000 mPa · s, and particularly preferably 200 to 2,500 mPa · s. Therefore, the water dispersion step becomes easy.

The aqueous anchor coating agent of the present invention includes known additives such as dyes, pigments, inorganic or organic fillers,
Antioxidants, ultraviolet absorbers, catalysts, preservatives, antibacterial agents, stabilizers, thixotropic agents, solvents, flame retardants, hydrolysis inhibitors, lubricants, plasticizers, storage stabilizers and the like can be added.

The water-based anchor coating agent of the present invention can be used as a one-liquid type. Specifically, it is generally used by dispersing it in water, applying it to a substrate, drying it and then laminating it with an extrusion resin. Target. After water dispersion,
It is essential to apply to the substrate while the isocyanate groups remain.

The pot life after water dispersion is 5 in the case of the conventional water-based anchor coating agent composed of the water-based polyisocyanate.
The time was about 7 hours or more, and in some cases, 10 hours or more, which was significantly improved with the aqueous anchor coating agent of the present invention. Therefore, in the actual extrusion laminating work, the water-based anchor coating agent dispersed in water in the morning can be used until the evening, and the raw material loss is greatly reduced.
Further, there is an advantage that the number of water dispersion operations per day can be reduced.

The aqueous anchor coating agent of the present invention can be used as an aqueous two-component system in which an aqueous resin further containing an alcoholic hydroxyl group is used in combination. In the case of an aqueous two-liquid system, a water-soluble resin containing an alcoholic hydroxyl group and / or an aqueous emulsion is used as a main component, and the above-mentioned polyisocyanate serves as a curing agent.

The above-mentioned water-soluble resin includes polyvinyl alcohol, polyethylene oxide, water-soluble ethylene-vinyl acetate copolymer, water-soluble acrylic resin, water-soluble epoxy resin, water-soluble cellulose derivative, water-soluble, which has an alcoholic hydroxyl group. Examples thereof include polyesters, water-soluble lignin derivatives, water-soluble fluororesins, water-soluble silicone resins and the like.

The aqueous emulsion includes all of what is called a latex or emulsion. For example, a styrene butadiene copolymer latex, an acrylonitrile butadiene copolymer latex, a methyl methacrylate butadiene copolymer latex, a chloroprene latex, a rubber latex such as a polybutadiene latex, or a polyacrylate latex having an alcoholic hydroxyl group. , Polyvinylidene chloride latex, polybutadiene latex, or those obtained by carboxyl-modifying these latexes. Also, polyvinyl chloride emulsion, urethane acrylic emulsion, silicone acrylic emulsion, vinyl acetate acrylic emulsion, polyurethane emulsion, acrylic emulsion, fluorine emulsion. Etc.

In the case of an aqueous two-component system, the main agent and the curing agent can be added as they are, once the aqueous resin curing agent is dispersed in water and then mixed, or after being dissolved in a solvent commonly used in the urethane industry. A method of blending may be mentioned. A preferred method is to disperse the curing agent in water before blending.

In the aqueous two-component system agent, the mixing ratio of the main agent and the curing agent is such that the solid content mass ratio is the main agent / curing agent = 0.5 /
100-100 / 100, preferably 1 / 100-50
/ 100.

If desired, the water-based anchor coating agent of the present invention may contain additives and auxiliaries commonly used in water-based systems. For example, pigments, dyes, dispersion stabilizers, viscosity modifiers, leveling agents, anti-gelling agents, light stabilizers, antioxidants, ultraviolet absorbers, heat resistance improvers, inorganic and organic fillers, plasticizers, lubricants, An antistatic agent, a reinforcing material, a catalyst and the like can be added.

The method of applying the anchor coating agent of the present invention is not particularly limited, and the one-liquid type is a dispersion liquid after water dispersion, and the two-liquid type is a liquid after mixing the main agent and the curing agent.
Examples of the coating method used for coating the substrate include roll coating, spray coating, knife coating and the like.

After coating the base material with the anchor coating agent, it is dried, laminated with a molten resin and pressure-bonded to obtain a laminated film. The application amount of the anchor coating agent is 1 to 10
g / m ² (wet) is preferable, and 2-5 is particularly preferable.
g / m ² (wet). Drying temperature is 50-120 ℃
Is preferable, and particularly preferably 60 to 100 ° C. Although the melting temperature of the resin having the optimum surface oxidation degree varies depending on the type, it is generally preferably 250 to 350 ° C, and particularly preferably 280 to 330 ° C. Crimping condition is 30
To 200 N / cm is preferable, and 40 to 1 is particularly preferable.
It is 00 N / cm. The air gap (distance from the die to the substrate) is preferably 80 to 150 mm, particularly preferably 90 to 120 mm. Chill roll temperature is 10-5
0 degreeC is preferable and 15-40 degreeC is especially preferable.
The processing speed (line speed) is preferably 80 to 200 m / min, particularly preferably 80 to 180 m / min.

[0059]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the examples and comparative examples, "%"
Means "mass%".

[Production of Polyisocyanate] Synthesis Example 1 90.0 kg of hexamethylene diisocyanate (HDI) was added to a reactor having a capacity of 100 L equipped with a stirrer, a thermometer, a cooler and a nitrogen gas introducing tube, 1,3- 0.72 g of butanediol was charged, the inside of the reactor was replaced with nitrogen, and the mixture was heated to a reaction temperature of 80 ° C. with stirring and reacted for 2 hours.
The isocyanate content of the reaction solution at this time was measured and found to be 48.9%. Next, 0.02 kg of potassium caprate as an isocyanurate-forming catalyst and 0.1 kg of phenol as a co-catalyst were charged, and an isocyanurate-forming reaction was carried out at 60 ° C. for 5 hours. To this reaction solution, 0.013 g of phosphoric acid was added as a terminating agent, and after stirring for 1 hour at the reaction temperature, unreacted HDI was added at 120 ° C. and 0.04 kPa.
The polyisocyanate A-1 was obtained by removal by thin film distillation under the conditions of. A-1 is a pale yellow transparent liquid having an isocyanate content of 21.3% and a viscosity at 25 ° C. of 2,400 mP.
a · s, free HDI content = 0.4%, average number of functional groups =
3.7, yield = 32%. In addition, FT-IR and
The presence of an isocyanate group, an isocyanurate group and a urethane group was confirmed by ¹³ C-NMR, but no uretdione group was confirmed. Therefore, the isocyanurate group content calculated from the isocyanate content is 27.7.
It became%. The same capacity as above: 800 A-1 in a 1 L reactor
g, 128 g of methoxypolyethylene glycol having a number average molecular weight of 400, and reacted at 80 ° C. for 4 hours,
Polyisocyanate AD-1 was obtained. The isocyanate content of AD-1 is 16.9% and the viscosity at 25 ° C is 2,500.
It was mPa · s.

[Production of Hydrophobic Polyisocyanate] Synthesis Example 2 Similar to Synthesis Example 1 Capacity: 100 L reactor with 9 HDI
Charge 0.0kg, 10.0kg methanol, 90 ℃
The urethane reaction was carried out for 2 hours. The reaction product is FT-
When analyzed by IR, the hydroxyl groups had disappeared. Next, 0.02 kg of zirconium 2-ethylhexanoate was charged and reacted at 90 ° C. for 3 hours. The reaction product is FT-
When analyzed by IR and ¹³ C-NMR, the urethane group had disappeared. Next, 0.01 kg of phosphoric acid was charged and a termination reaction was performed at 50 ° C. for 1 hour. The isocyanate content of the reaction product after the termination reaction was 31.9%. This reaction product was subjected to thin film distillation at 130 ° C. × 0.04 kPa to obtain hydrophobic polyisocyanate B-1. B-1
Has an isocyanate content of 20.9% and a viscosity at 25 ° C of 1
20 mPa · s, average number of functional groups is 2.0, free HDI
The content was 0.1%. In addition, B-1 is FT-IR
And ¹³ C-NMR analysis, no urethane group was confirmed and the presence of allophanate group was confirmed. Further, the uretdione group and the isocyanurate group were in traces. The results are shown in Table 1.

Synthesis Examples 3 and 4 In the same manner as in Synthesis Example 1, hydrophobic polyisocyanates B-2 and 3 were produced using the raw materials shown in Table 1. The results are shown in Table 1.

[0063]

[Table 1]

In Table 1 MeOH: Methanol IPA: Isopropyl alcohol 2EHOH: 2-ethyl-hexyl alcohol HDI: Hexamethylene diisocyanate Zr-2EH: Zirconium 2-ethylhexanoate

[Production / Evaluation of Aqueous Anchor Coating Agent] Examples 1 to 6 and Comparative Examples 1 to 4 A reactor having the same capacity as that of Synthesis Example 1 of 1 L was charged with each polyisocyanate at the compounding ratio shown in Table 2. Aqueous anchor coat agents AC-1 to 6 were prepared. The obtained aqueous anchor coating agent was dispersed in water, the isocyanate content was measured every hour, and the pot life was measured. Further, for comparison, A-1 and B-1 to 3 were similarly evaluated.
The results are shown in Table 2. Since B-1 to B-3 were not dispersed in water, the pot life could not be measured. Pot life measurement conditions Mixing ratio: Water / polyisocyanate = 270 g / 30 g Dispersion method: After mixing, 2,000 rpm × with a homomixer
30 seconds stirring measurement temperature: 25 ° C

[0066]

[Table 2]

From Table 2, the hydrophilic polyisocyanate,
It was found that the polyisocyanate composition obtained by mixing the hydrophobic polyisocyanate has a longer pot life than that of the hydrophilic polyisocyanate alone.

[Extrusion Lamination Evaluation] Coating liquids were prepared with the formulations shown in Tables 3 and 4. The one-liquid type coating liquid was evaluated by dispersing AC-1 to AC-6 and A-1 in water, and immediately after the dispersion and 7 hours after the dispersion. The two-liquid type coating liquid was evaluated immediately after the dispersion of AC-2, 5 and A-1 in water and 7 hours after the dispersion. This coating solution was applied to a nylon film, water was evaporated in a drying oven, and then the extruded low-density polyethylene resin and the corona-treated unstretched low-density polyethylene film were simultaneously attached. Then, the laminate film was obtained by aging at 40 ° C. for 24 hours. The laminated film thus obtained was tested for adhesive strength and boil resistance after being filled with food. The results are shown in Table 3.

Lamination conditions Film composition: NY / AC / exLDPE / LLDPE where NY: corona-treated stretched nylon film (thickness 15 μm) AC: aqueous anchor coat agent exLDPE: extruded low-density polyethylene resin (thickness 20 μm) LLDPE: corona-untreated Stretched linear low-density polyethylene film (thickness 60 μm) Laminating conditions Air gap: 115 mm Chill roll temperature: 18 ° C. Extrusion resin temperature: 310 ° C. Line speed: 100 m / min Coating amount of coating liquid: 4 g / m ² wet temperature: Drying temperature: 95 ° C

Adhesive Strength Test The above test sample was cut into a width of 15 mm, and a peel strength between nylon and a low density polyethylene resin was subjected to a T-type peel test at a tensile speed of 300 mm / min using a Tensilon tensile tester manufactured by Orientec. .

Boil Resistance Test A bag prepared by the above test sample was filled with a model food in which commercially available 4.2% vinegar, salad oil and ketchup were mixed in 1/1/1. The bag was boiled in hot water at 90 ° C. for 1 hour, the contents were taken out, and the peel strength was measured in the same manner as in the above adhesive strength test.

[0072]

[Table 3]

[0073]

[Table 4]

In Table 4 WOE-305: Water-based polyurethane resin containing alcoholic hydroxyl group                 Made by Nippon Polyurethane Industry                 Solid content = 40%

As is clear from the above test results, the partially acid-modified polyol and the water-based anchor coating agent of the present invention showed good performance, especially after a lapse of time from the water dispersion.

[0076]

The water-based anchor coating agent of the present invention is optimal as an anchor coating agent for extruded laminated films for food packaging materials, for example. In particular, the performance does not deteriorate even after a lapse of time after water dispersion, so that the raw material loss and workability are significantly improved. Further, it can be widely applied to the base film.

Continued front page    F-term (reference) 4J034 AA04 AA06 BA03 BA07 BA08                       CA02 CA03 CA04 CA05 CA24                       CA25 CB01 CC03 CC08 CC09                       CC12 CC13 CC26 CC45 CC61                       CC65 DB01 DB03 DB07 DF01                       DF02 DF12 DF14 DF19 DF32                       DG02 DG03 DG04 DG14 DG23                       DK01 DM01 DP02 DP03 DP12                       DP15 DP17 DP18 DP19 EA01                       EA08 EA09 EA12 HA02 HA06                       HA08 HC03 HC06 HC08 HC12                       HC13 HC35 HC46 HC52 HC61                       HC64 HC67 HC71 HC73 JA42                       KA01 KB01 KC16 KD02 QA02                       QA05 RA07                 4J038 BA021 CA051 CC041 CD031                       CD091 CE021 CG121 DB001                       DD001 DG051 DG081 DG111                       DG121 DG131 DG141 DG191                       DG271 DL001 GA03 MA08                       MA10 MA15 NA04 NA12 NA26

Claims (3)

[Claims] 1. A polyisocyanate (A) and (B) at least shown below in a mass ratio of (A) :( B) = 10 /
An aqueous anchor coating agent contained in a ratio of 90 to 90/10. (A): A polyisocyanate obtained by reacting an isocyanurate-modified polyisocyanate (A1) of hexamethylene diisocyanate with an alkylene oxide adduct (A2) containing at least a monool (containing at least 30 mol% of ethylene oxide). (B): The average number of functional groups is 2 to 3, and the viscosity at 25 ° C. is 50.
Polyisocyanates containing allophanate groups of 0 mPa · s or less. 2. (B) is obtained by reacting hexamethylene diisocyanate with an alcohol in the presence of a carboxylic acid zirconium salt,
The water-based anchor coating agent according to claim 1. 3. The aqueous anchor coating agent according to claim 1, further comprising an aqueous resin containing an alcoholic hydroxyl group.