JP2002294292A - Cleaning method for applicator and hot-melt cleaning composition used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning method effective in removing an adhesive, such as a moisture-curable hot-melt adhesive, remaining in an applicator after the use of the adhesive, etc.; and a hot-melt cleaning composition used therefor. SOLUTION: This cleaning method includes a step wherein a moisture-curable hot-melt adhesive remaining in an applicator is brought into contact with a hot-melt cleaning composition containing an organophosphorus compound and a nonreactive hot-melt adhesive and thermally melted or a step wherein a moisture-curable hot-melt adhesive is brought into contact with an organophosphorus compound, thermally melted, then brought into contact with a nonreactive hot-melt adhesive, and thermally melted. Preferably, the organophosphorus compound has a specific gravity of 1.1 or higher. The hot-melt cleaning composition is used in the cleaning method for an applicator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning an applicator and a hot melt composition for cleaning used in the method. More specifically, for example, a moisture-curable hot melt adhesive is supplied to a hot melt supply device (hereinafter referred to as "applicator"). After supplying the adhesive to a slit coater, a die coater, a nozzle gun, a spray gun, or the like using the above method, and a method of cleaning the applicator by removing the moisture-curable hot-melt adhesive remaining inside the applicator and the method thereof And a hot-melt composition for cleaning.

[0002]

2. Description of the Related Art Generally, hot-melt adhesives have a process or economical advantage of being capable of instantaneous bonding and high-speed bonding without using a solvent. It is used in large quantities as a subject. As the base polymer of the hot melt adhesive, EVA (ethylene-vinyl acetate copolymer), EEA
Ethylene copolymers such as (ethylene- (meth) acrylate copolymer), polyethylene, polypropylene, APAO (amorphous polyalphaolefin)
In addition to synthetic rubbers such as olefin resins such as SIS (styrene-isoprene-styrene copolymer) and SBS (styrene-butadiene-styrene copolymer) and hydrogenated products thereof, polyester resins and polyamide resins are used. Have been.

The above-mentioned hot melt adhesive is called a thermoplastic type. In addition, as a post-crosslinking type hot melt adhesive by moisture curing, the base polymer, for example, an isocyanate group or a urethane prepolymer is used. Those into which silyl groups have been introduced are called moisture-curable hot melt adhesives and are widely used. Moisture-curable hot-melt adhesives typified by these moisture-curable urethane-based hot-melt adhesives are usually in a solid state at room temperature, but are all in a solid state at the time of use. The adhesive in a state where the adhesive has been heated and melted to have an appropriate viscosity is supplied to various coating machines and used.

[0004] Usually, this applicator has a charging port for charging an adhesive, a melting tank for heating and melting, and an operating facility for supplying the molten adhesive. There is also an applicator of a type in which an adhesive contained in a pail or drum can is melted by a hot plate and supplied.

[0005] In particular, in the case of an applicator for using a moisture-curable hot-melt adhesive, in addition to the function of the above-described applicator, it is necessary to suppress contact between the adhesive and outside air (particularly moisture). Some measures have been taken to increase the airtightness of the adhesive inlet and to enable the inside of the tank to be periodically replaced with nitrogen, carbon dioxide, or the like. In particular, with regard to the method of nitrogen replacement, in the past, only periodic nitrogen replacement was conventionally used, but in recent equipment, an efficient replacement method such as once reducing the pressure in the tank and replacing the tank has been studied. .

However, moisture-curable hot-melt adhesives usually have a tendency to undergo a curing reaction by heat in addition to moisture-curing. Therefore, if the applicator is used for a long time, the inside of the applicator melting tank or the inside of a hose may be damaged. In this case, curing gradually progressed, and supply was impossible due to clogging, mixing of gel components, and the like, and sufficient bonding work was not performed in some cases.

As a general means for solving the above-mentioned problems, for example, a non-reactive hot-melt composition having no moisture-curing property is used as a detergent, and a moisture-curing type Japanese Patent Application Laid-Open No. H7-17-1 discloses that a method of replacing and washing with a hot melt adhesive is performed.
No. 97006 is disclosed.

[0008]

However, according to the study of the present inventors, even with these methods, the inside of the applicator may not always be completely washed, and the applicator still remains in the melting tank. In some cases, problems such as skin sticking and gelation caused by the moisture-curable hot melt adhesive occurred.

The present invention has been made in view of the above problems, and is an effective method for removing an adhesive or the like remaining inside an applicator after using a moisture-curable hot melt adhesive or the like. A method for cleaning an applicator and a hot melt composition for cleaning, which do not cause problems such as skin sticking or gelling due to a residual adhesive or the like in an applicator melting tank, and do not cause clogging or gel mixing in a melting tank or a hose. The purpose is to provide things.

[0010]

According to a first aspect of the present invention, there is provided a method for cleaning an applicator, wherein an organic phosphorus compound and a non-reactive hot melt adhesive are contained in a moisture-curable hot melt adhesive remaining inside the applicator. The method is characterized by including a step of bringing a hot melt composition for cleaning into contact with the composition and heating and melting the composition. The method for cleaning an applicator according to claim 2 includes a step of bringing an organic phosphorus-based compound into contact with a moisture-curable hot melt adhesive, heating and melting the same, and then contacting and heating and melting a non-reactive hot melt adhesive. It is characterized by. The method for cleaning an applicator according to claim 3,
The method for cleaning an applicator according to claim 1 or 2, wherein the specific gravity of the organic phosphorus compound is 1.1 or more. The hot melt for cleaning used in the method for cleaning an applicator according to claim 1, wherein the hot melt composition for cleaning according to claim 4 comprises an organic phosphorus compound and a non-reactive hot melt adhesive. A composition.

The details of the present invention will be described below. The organic phosphorus compound used in the present invention is not particularly limited, and an organic phosphorus compound usually used for a PVC resin or the like is used.For example, tricresyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, Tris (isopropylphenyl) phosphate, cresyl diphenyl phosphate, triphenyl phosphite, triphenyl phosphine, triphenyl phosphine oxide and the like can be mentioned. Further, when the specific gravity of the organic phosphorus compound is 1.1 or more, the adhesive remaining on the bottom of the melting tank is more easily removed, and thus it is more preferable. For example, triphenyl phosphate, triphenyl phosphine, triphenyl phosphine, etc. Fin oxide and the like.

The non-reactive hot-melt adhesive in the present invention is not particularly limited as long as it is a non-moisture-curable type in which an isocyanate group or a silyl group is not introduced. Those composed of a thermoplastic resin, a tackifier resin, waxes, a softener, and the like are preferably used. These may be used alone or 2
Species or more may be used as a mixture.

As the thermoplastic resin, those conventionally known as a base polymer for a hot melt adhesive can be used. For example, EVA (ethylene-vinyl acetate copolymer) and ethylene-acrylate copolymer may be used. Polymer, ethylene-methacrylate copolymer, ethylene-n-butylacrylate copolymer, SBS
(Styrene-butadiene-styrene copolymer), SIS
(Styrene-isoprene-styrene copolymer), SEB
Thermoplastic rubber such as S (styrene-ethylenebutylene-styrene copolymer), SEPS (styrene-ethylenepropylene-styrene copolymer), or polyolefin resin such as polyethylene, polypropylene, α-olefin copolymer, etc. Can be

Examples of the tackifying resin include aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, aromatic hydrocarbon resins, polyterpene resins, rosin resins, styrene resins, and cumarone resins. Examples thereof include those conventionally known in the field of hot melt adhesives such as indene resin.

Examples of the waxes include synthetic waxes such as Fischer-Tropsch wax, polyethylene wax, polypropylene wax, atactic polypropylene and ethylene-vinyl acetate copolymer; petroleum waxes such as paraffin wax and micro wax; Natural waxes such as carbana wax and beeswax, higher alcohols such as lauryl alcohol, oleyl alcohol and stearyl alcohol, and hydroxyl group-containing waxes derived from natural / synthetic fats and oils, and reduced oils and fats of natural fats and oils containing these. Etc. can be used. Among the synthetic waxes mentioned here, there are those having the same structural formula as the above-mentioned thermoplastic resin, but here, those having a low molecular weight such that MI (melt index) cannot be measured are meant.

The softening agent is not particularly limited, but includes ordinary paraffinic oils, naphthenic oils, aromatic oils and the like.

According to the present invention, the moisture-curable hot melt adhesive remaining in the applicator after the adhesive is supplied to a coater or the like using a supply device such as an applicator as described above. Although it is related to the cleaning method to remove, as the moisture-curable hot melt adhesive used in this case, for example, the terminal obtained by reacting an organic polyol compound with an organic polyisocyanate compound or a silane coupling agent, etc. An adhesive containing a urethane prepolymer having an isocyanate group or a hydrolyzable silyl group may be used.

As the above-mentioned organic polyol compound, known compounds usually used in the production of polyurethane can be used.
Examples include polyether polyol, polyalkylene polyol, and polycarbonate. Examples of the polyester polyol include terephthalic acid, isophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, deca Methylene dicarboxylic acid, polyvalent carboxylic acid such as dodecamethylene dicarboxylic acid, ethylene glycol, propylene glycol, 1,
3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,
Examples include polyester polyols obtained by reaction with polyols such as 6-hexanediol, diethylene glycol and cyclohexanediol, and poly-ε-caprolactone polyols obtained by ring-opening polymerization of ε-caprolactam.

Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like. Examples of the polyalkylene polyol include polybutadiene polyol, hydrogenated polybutadiene polyol, hydrogenated polyisoprene polyol, and the like. Is mentioned.
Examples of the polycarbonate polyol include polyhexamethylene carbonate polyol and polycyclohexane dimethylene carbonate polyol. These organic polyol compounds described above may be used alone or in combination of two or more.

Examples of the organic polyisocyanate compound include liquid modified products such as tolylene diisocyanate, diphenylmethane diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexane phenylene diisocyanate, and naphthalene-1,5-diisocyanate. Can be Among these polyisocyanates, diphenylmethane diisocyanate and its modified products are preferred from the viewpoints of vapor pressure, toxicity, and ease of handling.

Examples of the silane coupling agent include γ-aminopropylmethyldiethoxysilane, γ
-Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-aminoethylaminopropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, mercapto Ethyltriethoxysilane, γ-mercaptopropyltrimethoxysilane and the like can be mentioned.

According to the method for cleaning an applicator of the present invention, the moisture-curable hot melt adhesive remaining inside the applicator contains an organic phosphorus compound and a non-reactive hot melt adhesive. A hot-melt composition for washing, which is heated and melted.For example, the organic phosphorus-based compound prepared beforehand is added to a melting tank of an applicator in which a moisture-curable hot-melt adhesive remains. It is preferable to use a method in which a hot-melt composition for cleaning containing a reactive hot-melt adhesive is charged, heated, melted, and discharged. However, in some cases, such as omitting the preparation of the hot melt composition for cleaning in advance, as in the method according to claim 2, for example, first, an organic phosphorus compound is charged into a melting tank and discharged after heating and melting. Then, a method may be used in which a non-reactive hot melt adhesive is charged, heated, melted, and discharged.

(Action) Since the method for cleaning an applicator of the present invention uses an organic phosphorus compound and a non-reactive hot melt adhesive, the organic phosphorus compound is cured by moisture, such as a moisture-curable urethane hot melt adhesive. In addition to inhibiting the reaction, the adhesive and the like remaining in the applicator melting tank when washing the moisture-curable hot melt adhesive can be prevented from gelling due to heat mixing due to moisture mixing and heating during washing, Since it is discharged together with the reactive hot melt adhesive, it can be cleaned very effectively. For this reason, it becomes possible to supply and apply a stable adhesive.

[0024]

EXAMPLES Hereinafter, the present invention will be specifically described by describing Examples and Comparative Examples. The present invention is not limited only to the following examples. Further, “parts” simply means “parts by weight”. <Preparation of moisture-curable hot melt adhesive> Sebacic acid 3
From 03 parts and 177 parts of 1,6-hexanediol, a milky white solid crystalline polyester polyol (having a hydroxyl value of 30) was obtained at room temperature by an esterification polycondensation reaction. Similarly, 30 parts of adipic acid and 134 parts of isophthalic acid (molar ratio is 20:80), and 10 parts of ethylene glycol and 80 parts of neopentyl glycol (molar ratio is 20:80) are subjected to esterification polycondensation, An amorphous polyester polyol (hydroxyl value: 55, Tg: 15 ° C) was obtained.

The above crystalline polyester polyol 40
0 part and 600 parts of amorphous polyester polyol
Melt kneading under heating at 20 ° C., dehydration under reduced pressure of 1 mmHg or less, temperature control at 100 ° C., and addition of 202 parts of MDI (diphenylmethane diisocyanate) [manufactured by Mitsubishi Chemical Corporation; did. The equivalent ratio [NCO] / [OH] between the isocyanate group of the MDI and the hydroxyl group of the polyol is 2.
0. After reacting for 3 hours, a microcrystalline solid urethane prepolymer was obtained at room temperature. This urethane prepolymer is referred to as a moisture-curable hot melt adhesive A.

<Preparation of Hot Melt Composition for Cleaning> EVA (ethylene-vinyl acetate copolymer) as a non-reactive hot melt adhesive [manufactured by Mitsui Dupont Polychemical Co., Ltd.
200 parts of trade name V-577-2], C-9 hydrogenated resin (alicyclic hydrocarbon resin) as a tackifying resin [manufactured by Arakawa Chemical Industry Co., Ltd., trade name of Alcon P-100] 200 parts, organic phosphorus-based resin TPP (triphenyl phosphate) as a compound
50 parts of [Daihachi Chemical Co., specific gravity 1.27] was melt-mixed at 130 ° C. to obtain a hot melt composition for cleaning.

<Preparation of Hot Melt Composition for Cleaning> EVA (ethylene-vinyl acetate copolymer) [manufactured by Mitsui Dupont Polychemical Co., Ltd.] as a non-reactive hot melt adhesive
200 parts of brand name V-577-2], 200 parts of C-9 hydrogenated resin (alicyclic hydrocarbon resin) as a tackifier resin (trade name of Alcon P-100 manufactured by Arakawa Chemical Industries, Ltd.), flowing as wax Melting and mixing 50 parts of paraffin [product name: Christol J352, manufactured by Esso Oil Co., Ltd.] at 130 ° C.
A hot melt composition for cleaning was obtained.

<Example 1> 4 kg of a moisture-curable hot melt adhesive A was used in a melting tank set at 120 ° C using PUR-203 manufactured by Meltex Co., Ltd. as an applicator.
After the charging, the adhesive was not discharged, and the mixture was purged with nitrogen every 30 minutes for 2 seconds (valve pressure: 20 kPa), and kept heated for 8 hours continuously, and then the adhesive was discharged from the hose connection port. Next, 4 kg of the hot-melt composition for cleaning was put into a tank, heated and melted, and then discharged from the hose connection port.

<Example 2> Using PUR-203 manufactured by Meltex Co., Ltd. as an applicator, 4 kg of a moisture-curable hot melt adhesive A was placed in a melting tank set at 120 ° C.
After the charging, the adhesive was not discharged, and the mixture was purged with nitrogen every 30 minutes for 2 seconds (valve pressure: 20 kPa), and kept heated for 8 hours continuously, and then the adhesive was discharged from the hose connection port. Next, 500 g of triphenyl phosphate was added, and after heating and melting, the mixture was discharged from the hose connection port. Thereafter, the hot melt composition for cleaning 3.5 was further added.
kg was put into a tank, and after heating and melting, the mixture was discharged from a hose connection port.

<Comparative Example 1> A tank was washed in the same manner as in Example 1 except that the hot melt composition for washing was used. <Evaluation> After each step of the above Examples and Comparative Examples, the residue adhering to the bottom of the applicator melting tank was peeled off, the amount of the residue was measured, and the residue was dissolved in toluene heated at 60 ° C. for 3 hours ( (Toluene was used to have a solid content of 20 wt%), and the mixture was filtered through a 100 mesh filter, and the gel fraction and the filter residue were measured. Table 1 shows the results.

[0031]

[Table 1] As shown in Table 1, in Examples of the present invention, the filter residue of the moisture-curable hot melt adhesive in the applicator, the gel fraction was low, and skin sticking and gelation were suppressed as compared with the Comparative Example. Turned out to be.

[0032]

As shown in the above results, according to the method for cleaning an applicator of the present invention, when a moisture-curable hot melt adhesive is used in an applicator, the cleaning efficiency is extremely high. Problems such as skin sticking, gelation, and coating unevenness due to agent residue hardly occur, daily maintenance becomes easy, and stable production becomes possible.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H003 DA12 DB03 EB24 EB28 EB30 EB33 FA21 4J040 BA171 BA181 BA201 DA031 DA111 DE031 DF031 DK011 DM011 DN071 EF111 EF121 EF131 EF291 EF301 EK072 GA05 GA11 HD14 J20 HD24 HDB KA16 KA25 KA31 LA06 MA02 MA03 MB09 NA12 PA30

Claims (4)

[Claims] 1. A step of contacting a hot-melt cleaning composition containing an organic phosphorus compound and a non-reactive hot-melt adhesive with a moisture-curable hot-melt adhesive remaining inside an applicator, followed by heating and melting. A method for cleaning an applicator, comprising: 2. An applicator characterized in that it comprises a step of bringing an organic phosphorus compound into contact with a moisture-curable hot-melt adhesive and melting it by heating, and then contacting a non-reactive hot-melt adhesive and melting it by heating. Cleaning method. 3. The method for cleaning an applicator according to claim 1, wherein the specific gravity of the organic phosphorus compound is 1.1 or more. 4. The hot-melt cleaning composition for use in a method for cleaning an applicator according to claim 1, comprising an organic phosphorus compound and a non-reactive hot-melt adhesive.