JP3361272B2 - One-component moisture-curable urethane adhesive - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-component moisture-curable urethane adhesive.

[0002]

2. Description of the Related Art As a conventional method for producing a one-component moisture-curable urethane adhesive, an isocyanate-terminated urethane prepolymer is synthesized by allowing excess isocyanates to act on previously dehydrated polyols, and then preparing the prepolymer. In addition, various modifiers such as a filler, a tackifying resin and a viscosity improver were blended. In this case, the prepolymer is mixed with the above-mentioned various modifiers after the step of removing water separately after being transferred to the processing pot. Therefore, at least a two-step process of urethanization reaction and mixing processing is required,
Water management such as dehydration treatment must be added in each step (hereinafter, this production method is referred to as "two-step method").

Further, in the two-step method which has been conventionally performed, the prepolymer itself has a good tack, while the initial setting as an adhesive, that is, the initial tack is very important as the required performance. However, if a filler such as calcium carbonate or a viscosity modifier is blended, the interaction with the prepolymer will be insufficient, and the initial tack will be significantly lost. It is difficult to develop the initial tack in the one-part moisture-curable urethane adhesive.

On the other hand, according to the publication, there is proposed a method in which various modifiers are mixed with polyols, a solvent or the like is added thereto, and dehydration is carried out by means such as azeotropic distillation, and then polyisocyanates are allowed to act. ing. According to such a method, facility modification and investment are necessary, but since the urethane reaction and processing can be integrated, water management is small and the number of steps is also small, so it can be said that it is a rational and progressive method. However,
This new proposal is just about streamlining manufacturing,
No mention is made of the difference in properties from the two-step method urethane composition.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to improve the adhesiveness and initial tack of a one-component moisture-curable urethane adhesive, and to provide good coating workability without adding a viscosity modifier. It is to give. Incidentally, the initial tack described here refers to the strength of the tack at the initial stage, which is indispensable as an adhesive, its expression speed, and a comprehensive initial adhesive property in which the duration is combined, and hereinafter, the initial tack of the present invention is , This characteristic.

[0006]

DISCLOSURE OF THE INVENTION As a result of earnest studies on the above-mentioned problems, the present inventors have made a urethane prepolymer obtained by reacting polyols and excess polyisocyanates in the presence of surface-treated calcium carbonate. Only when a polymer was used, it was found that the adhesiveness, initial tack, coating workability, and the like were significantly superior to those of the one-component moisture-curing urethane adhesive obtained from the conventional two-step method.
Subsequently, the inventors of the present invention, as a further improvement of the present invention, can obtain better coating workability by using a specific surface-treated calcium carbonate, and also use polyether polyol and polyester polyol in combination as polyols. Therefore, it was found that the initial tack is improved, the viscosity of the adhesive is reduced, and the excellent balance between the adhesiveness and the excellent effect is exhibited. Further, they have found that the use of a hydroxyl group-containing xylene resin as a part of the polyether polyol and the polyester polyol makes it possible to achieve an excellent early development of the initial tack, thus completing the present invention.

That is, the means for solving the above problems of the present invention are as follows. According to the invention of claim 1,
An isocyanate-terminated urethane prepolymer obtained by reacting a polyol and an excess polyisocyanate in the presence of calcium carbonate, which has been surface-treated, is used to achieve high adhesion and excellent initial tack and coating workability. Liquid moisture curing type urethane adhesive.

According to the invention of claim 2, the surface-treated calcium carbonate in the means of claim 1 has a viscosity ratio of 2.0 or more at 28 ° C. when it is made into a 15 wt% dioctyl phthalate dispersion. The adhesive is a one-component moisture-curable urethane-based adhesive having high adhesiveness and excellent initial tack and coating workability according to the means of claim 1. That is, it is a technical means for further improving the coating workability by using the above calcium carbonate having a viscosity ratio at 28 ° C. of 2.0 or more.

According to a third aspect of the present invention, the polyols according to the first aspect comprises a mixture of a polyether polyol and a polyester polyol.
Alternatively, it is a one-component moisture-curable urethane-based adhesive having high adhesiveness and excellent initial tack and coating workability according to the second aspect. By using the polyols in this range, a low-viscosity composition that is particularly excellent in strength and development speed in the initial tack can be obtained, and the coating workability is further improved.

According to the invention of claim 4, a xylene resin containing a hydroxyl group is used as a part of the polyether polyol and the polyester polyol in the means of claim 3 with high adhesiveness in the means of claim 3. A one-component moisture-curing urethane adhesive with excellent initial tack and coating workability. By partially blending this xylene resin, not only the expression speed of the initial tack in the effect described in claim 3 is further improved, but also its duration is prolonged.

In the invention of claim 5, the xylene resin having a hydroxyl group in the means of claim 4 is an addition condensation oligomer of meta-xylene and formaldehyde and / or a modified product thereof. It is a one-part moisture-curing urethane adhesive with high adhesiveness and excellent initial tack and coating workability. Within this range, application workability, initial tack strength and development speed, extension of duration, etc. are most suitable for the purpose of the present invention.

The polyol which is the starting material of the urethane prepolymer of the present invention can be classified into polyether polyol and polyester polyol. That is, examples of the polyether polyol having an ether bond in the molecule include polyoxyalkylene diol (specifically, polyoxyethylene glycol, polyoxypropylene glycol, polyoxybutylene glycol, etc. and their copolymers), polyoxyalkylene. Starting materials include polyoxyalkylene polyols such as triols (specifically, those obtained by addition polymerization of ethylene oxide, propylene oxide, butylene oxide, styrene oxide, etc. with glycerin, trimethylolpropane, etc.) and other bisphenols, sugars, amines, etc. Examples include diols added with ethylene oxide or propylene oxide, polyether polyols, and polyoxytetramethyl glycol obtained by ring-opening polymerization of tetrahydrofuran. It can be.

Of these, polyoxyalkylene diols and polyoxyalkylene triols are preferably used because of low viscosity and easy liquefaction.

As the polyester polyol, conventionally known ones can be widely used as long as they are compounds having an ester bond as a repeating unit in the molecule and having a hydroxyl group at the terminal. Specifically, a condensation polyester polyol obtained by dehydration condensation of a polyvalent carboxylic acid (mainly adipic acid or phthalic acid) and a polyhydric alcohol (specifically glycol, triol, etc.); ring-opening polymerization of ε-caprolactone A lactone-based polyester polyol obtained by: a polycarbonate diol obtained by phosgenation of a polyol or a transesterification reaction with diphenylene carbonate; a polyester polyol obtained by a polyaddition reaction of a polycarboxylic acid anhydride and diepoxide;
Examples thereof include urethane-modified polyester polyols in which a urethane group or the like is introduced inside the molecule.

Of these, ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol and 1,6-
It is preferable to use a condensed polyester polyol obtained by a condensation reaction of a polyhydric alcohol such as hexanediol and neopentyl glycol with a polycarboxylic acid such as adipic acid, sebacic acid, isophthalic acid and trimellitic acid.

In addition to the above, conventionally known compounds that can be used as so-called polyols having a hydroxyl group in the molecule can be used. Specifically, hydroxyl-terminated polybutadiene (1,2-addition product, 1,4-addition product), so-called rosin-modified polyol having a rosin skeleton in the molecule, amine polyol having an amine structure in the molecule, carbinol-modified silicone. So-called silicon-based diols in which carbinol is introduced into both ends of polysiloxane called oil, so-called acrylic polyols having acrylic acid ester (including methacrylic acid ester) as a skeleton, and fluorine resin (for example, difluoride) as a skeleton. Examples thereof include so-called fluororesin-based polyols having a hydroxyl group at the terminal of ethylene / acrylic copolymer resin).

As the polyisocyanate used in the present invention, an aliphatic, aromatic or alicyclic polyisocyanate compound having a plurality of isocyanate groups in the molecule, preferably having an average of 2 to 3 isocyanate groups is used.

Specifically, for example, 2,4-toluene diisocyanate (hereinafter referred to as "2,4-TDI"),
2,6-Toluene diisocyanate (hereinafter referred to as "2,6-
TDI ”. ), 2,4-TDI and 2,6-TDI
An isomer mixture of 4,4'-diphenylmethane diisocyanate (hereinafter referred to as "4,4'-MDI").
2,4'-diphenylmethane diisocyanate (hereinafter referred to as "2,4'-MDI"), isomer mixture of 4,4'-MDI and 2,4'-MDI, carbodiimide-modified MDI, polymethylene polyphenyl polyisocyanate (This corresponds to a crude product of 4,4′-MDI and is hereinafter referred to as “polymeric MDI” or “crude MDI”),
Hexamethylene diisocyanate (hereinafter "HMDI")
Say. ), Xylene diisocyanate (hereinafter, “XD
I ". ), Meta-xylene diisocyanate, 1,
5-Naphthalene diisocyanate, hydrogenated TDI, hydrogenated MDI, hydrogenated XDI, isophorone diisocyanate and other isocyanate compounds; Sumidule N (manufactured by Sumitomo Bayer Urethane Co.) and other buret polyisocyanate compounds; Desmodur IL, HL (Bayer A. G.
Manufactured by Nippon Polyurethane Industry Co., Ltd.)
Polyisocyanate compounds having an isocyanate ring such as Sumijour L (manufactured by Sumitomo Bayer Urethane Co.) and Coronate HL (manufactured by Nippon Polyurethane Industry Co., Ltd.).

Among these, 4,4'-MDI and crude products thereof, a mixture of 4,4'-MDI and 2,4'-MDI and the use of these crude products have a high initial tack strength, It is preferable in terms of adhesiveness, adhesive strength, and good coating workability.

The isocyanate-terminated urethane prepolymer is usually synthesized by reacting the above polyols with an excess of polyisocyanate. There is no particular limitation on the synthetic method, and it may be produced by a conventionally known method.

The excess polyisocyanate referred to in the present invention means that the isocyanate group equivalent is in excess of the hydroxyl group equivalent of the polyol, and the equivalent relationship is NCO / O.
It can be represented by the H ratio. That is, theoretically NCO
When the / OH ratio exceeds 1, it may be terminated with an isocyanate, but the present invention is characterized by being excellent in coating workability, so that it is preferably liquid, and usually the NCO / OH ratio is preferably 1.5 or more. . The upper limit of the NCO / OH ratio is not particularly limited, but the NCO / OH ratio is 1
0.0 or less is preferable. The reason for this is that the NCO / OH ratio is 1
This is because if it exceeds 0.0, the isocyanate group becomes excessive, which causes adverse effects such as delay of curing and increase of foaming during moisture curing. Further, in order to obtain a liquid prepolymer having a low viscosity, it is particularly preferable to adjust the NCO / OH ratio to 2.0 to 10.0 while considering the type of polyol, the number of functional groups, the molecular weight and the like.

The urethane reaction temperature and the reaction time thereof are not particularly limited, but usually, it is preferable to mix the polyol and the surface-treated calcium carbonate with polyisocyanate under a nitrogen stream and then react at 60 to 100 ° C. for 3 to 8 hours. . In the reaction, an organometallic salt-based urethane catalyst such as dibutyltin dilaurate may be added in any suitable amount at any stage.

The surface-treated calcium carbonate (hereinafter sometimes abbreviated as "treated carbon") in the present invention means a compound such as a fatty acid type, a resin acid type, an alkyl benzene sulfonic acid type, or a rosin acid type surface. It is calcium carbonate whose surface is treated as a treating agent.

A method for preparing a 15% by weight dioctyl phthalate (hereinafter referred to as "DOP") dispersion in the present invention and a method for determining its viscosity ratio will be described below. To 150 parts by weight of surface-treated calcium carbonate, 850 parts by weight of DOP was added, and after roughly kneading with a stirring rod or the like, an auto homomixer (trade name T.M. K homomixer HV-M; manufactured by Tokushu Kika Kogyo Co., Ltd.). At that time, the stirring speed was gradually increased to the dial 6, and the stirring was continued for 120 seconds at the rotation speed to uniformly disperse. The temperature of the thus obtained dispersion is adjusted to 28 ° C., and the viscosity is measured using a BM type viscometer (trade name: Viscometer BM; manufactured by Tokimec) as a viscosity measuring device. Among the measured values, the viscosity values of the rotation speed of the measuring terminal of 6 r / min and 60 r / min are adopted. The viscosity ratio of the present invention is the ratio of these values, that is, (viscosity value of 6 r / min): (60 r / min.
min value), that is, the viscosity ratio = (viscosity value of 6 r / min) / (60 r / m)
in viscosity value).

Among the surface-treated calcium carbonates of the present invention, those which further improve the coating workability while maintaining the adhesiveness and initial tack which are the features of the present invention are 15% by weight.
It can be identified by the viscosity ratio of the DOP dispersion liquid. When the viscosity ratio of the present invention is 2.0 or less, workability such as trowel separation tends to be slightly lowered.

The amount of the surface-treated calcium carbonate used in the present invention is 10 parts by weight based on 100 parts by weight of the prepolymer.
˜250 parts by weight, preferably 20 to 200 parts by weight is mixed to obtain a one-component moisture-curable urethane adhesive. If it is less than 10 parts by weight, the economic effect and the reinforcing effect due to the increase in the amount of the filler cannot be expected. On the other hand, when the amount is 250 parts by weight or more, the amount of the filler is too large and the tack effect originally possessed by the prepolymer is weakened, or the composition becomes extremely high in viscosity, and the coating workability is extremely deteriorated. The harmful effect of becoming.

In the present invention, a hydroxyl group-containing xylene resin that exhibits an excellent effect of improving initial tack is a xylene aldehyde resin synthesized from xylene and formaldehyde, a mesitylene aldehyde resin synthesized from mesitylene and formaldehyde, And a modified xylene formaldehyde resin modified with a third component such as phenol. Among these, an oligomer of meta-xylene (m-xylene among structural isomers of xylene) and formaldehyde, and an oligomer obtained by reacting the third component with it are suitable for the purpose of the present invention. The third component mentioned here includes polyol, alkylphenol, phenol, epoxy resin, and the like.

The rosin polyol in the present invention has approximately two rosin skeletons and two hydroxyl groups in the molecule.

In the present invention, the proportion of hydroxyl group-containing xylene resin and / or rosin polyol to replace the polyether polyol and polyester polyol is 1
% To 80% by weight. If it is less than 1% by weight, the effect of xylene resin on imparting initial tack cannot be sufficiently obtained, and if it is more than 80% by weight, it is extremely effective for the development of initial tack, but the viscosity of the prepolymer is high. It becomes too much and is not practical as an adhesive. As a range in which the effect of providing the initial tack of the xylene resin can be sufficiently exhibited and a practical viscosity range is exhibited, 5% by weight to 60% by weight is particularly preferable.

[0030]

In the invention according to the first aspect of the invention, first, calcium carbonate which is surface-treated with respect to polyols is mixed in a closed container in which moisture is shut off, and the mixture is sufficiently heated and dehydrated under reduced pressure. The conditions are, for example, 80 to 13
Decompression dehydration may be performed at 0 ° C. at 50 Torr or less for about 30 to 120 minutes. In this case, it does not hinder the removal of water by azeotropic distillation with the addition of some organic solvent. Next, under a stream of dry nitrogen, excess polyisocyanates were added to this, and ordinary urethane synthesis conditions (eg, 70 ° C. for 4 hours) were used.
Then, the urethane reaction is carried out. After that, if necessary, various modifiers such as a diluent, a plasticizer, a tackifying resin, an adhesiveness-imparting agent, a moisture binder, a curing catalyst, a stabilizer, a colorant, and an organic solvent are mixed and mixed and processed. Get the adhesive with.

When the surface-treated calcium carbonate is mixed with the polyols, various modifiers such as other inorganic fillers, plasticizers, tackifying resins, adhesiveness imparting agents, etc. are appropriately added as necessary. Among them, if it is not particularly volatilized or deteriorated during the heat dehydration treatment under reduced pressure, it may be blended in advance.

Since this adhesive becomes unstable due to the influence of moisture during the manufacturing process and storage, it is important to remove the moisture as much as possible from the raw material having moisture in the blending raw material in the dehydrating step so that the quality of the adhesive is long-term. It is preferable in terms of stability.

Examples of the diluent include petroleum hydrocarbon diluents and esters such as 3-methyl-3-methoxybutyl acetate and dimethyl glutarate.

Examples of the plasticizer include dioctyl phthalate, dibutyl phthalate, dilauryl phthalate,
Butylbenzyl phthalate, dioctyl adipate, diisodecyl adipate, trioctyl phosphate,
Mineral spirits and the like can be mentioned, and each can be used alone or as a mixture.

As the tackifying resin, conventionally known resins can be used. Specifically, for example, in natural resin-based tackifying resins, rosin resins such as rosin, modified rosin, and rosin ester; terpene resins such as terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, and terpene phenol resins are used. is there. In addition, synthetic resin tackifying resins include aliphatic (C5) petroleum resins and aromatic (C9) petroleum resins.
Type) petroleum resin, copolymer type (C5 / C9 type) petroleum resin, hydrogenated petroleum resin, DCPD type petroleum resin, etc .; coumarone / indene resin; styrene resin, substituted styrene resin, etc., pure monomer type petroleum resin A phenolic resin such as an alkylphenol resin or a rosin-modified phenolic resin; a xylene resin.

Of these, tackifying resins that are liquid at room temperature and tackifying resins that are solid and soluble in urethane prepolymers can be used, and solid resins having a softening point of 130 are preferred.
It is below ℃.

Examples of the adhesiveness-imparting agent include a silane coupling agent (γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, a reaction product of these compounds, etc.).

Examples of the water binder include tosyl isocyanate and zeolite.

Examples of the curing catalyst include bis (morpholinoethyl) ether, bis (2,6-dimethylmorpholinoethyl) ether, bis (3,5-dimethylmorpholinoethyl) ether, and other bis (morpholinoethyl) ethers. An amine-based urethane catalyst and an organometallic urethane catalyst such as dibutyltin dilaurate can be appropriately used according to the purpose. Of these, bis (2,6-dimethylmorpholinoethyl) ether is preferable because it develops initial tack particularly early.

As the stabilizer, tinuvin 326 or 2,4
-UV absorbers such as dihydroxybenzophenone, Zn
And metal chelates such as Ni-dibutyldithiocarbamate, azo compounds such as p-hydroxyazobenzene and p-aminoazobenzene, and the like, which may be appropriately used for the purpose of light stabilization.

Examples of the colorant include inorganic colorants such as titanium oxide, iron oxide, chromium oxide and lamp black, and organic dyes such as azo and diazo dyes, phthalocyanine and dioxazine. Although the organic solvent is not required in the present invention, it does not prevent the use of the organic solvent.

As the other inorganic fillers, inorganic compounds such as calcium carbonate, clay, talc, magnesium oxide, diatomaceous earth, and glass balloons whose surface is untreated can be appropriately used.

According to the invention of claim 2, the surface-treated calcium carbonate is identified by the above method as 15
An adhesive is obtained in the same manner as in claim 1 by using calcium carbonate having a viscosity ratio of the weight% DOP dispersion liquid at 28 ° C. of 2.0 or more.

According to the third aspect of the invention, a mixture of polyether polyol and polyester polyol is used as the polyols, and an adhesive is obtained by the same means as in the first aspect.

According to the invention of claim 4, a part of the polyether polyol and the polyester polyol is a xylene resin containing a hydroxyl group and / or a rosin polyol, and an adhesive is obtained by the same means as in claim 1.

In the invention according to claim 5, the addition polymerization oligomer of meta-xylene and formaldehyde and / or its modified product is used as the xylene resin.
An adhesive is obtained by the same means as in.

The adhesive thus obtained is usually stored under a dry nitrogen stream in a container such as an aluminum pack or a pail that can be closed. After the storage, the adhesive is taken out by a method such as squeezing and removing a spatula, and the adhesive is applied to the adherend and used as the adhesive. The coating method shall be selected appropriately according to the bonding work procedure.

Hereinafter, in order to more specifically show the present invention,
Examples will be described based on the embodiments of the invention.

[0049]

[Example] (Example 1) 5L planetary mixer (brand name planetary mixer PLM5; manufactured by Inoue Seisakusho)
And a bifunctional polypropylene glycol having a molecular weight of 2000 (trade name Takelac P-21; manufactured by Takeda Pharmaceutical Co., Ltd.) 50
0 parts by weight, molecular weight 3000 trifunctional polypropylene glycol (trade name Takelac P-31, manufactured by Takeda Pharmaceutical Co., Ltd.) 100 parts by weight, molecular weight 2000 bifunctional polyester polyol (trade name ADEKA NEW ACE F7-6)
7, Asahi Denka Kogyo Co., Ltd.) 200 parts by weight, hydroxyl group-containing xylene resin (trade name Nikanol H; Mitsubishi Gas Chemical Co., Inc.) 2
100 parts by weight of the DOP dispersion liquid of the present invention was added, and further 1000 parts by weight of surface-treated calcium carbonate having a viscosity ratio of 1.1 (trade name: Homocal DM; manufactured by Shiraishi Kogyo Co., Ltd.) was added, and the mixture was sufficiently heated with steam under reduced pressure. Dehydrated. When cooled and the liquid temperature dropped to 50 ℃, under dry nitrogen flow, 4, 4 '
591 parts by weight of a mixture containing half of each of -MDI and 2,4'-MDI was added, and a urethanization reaction was performed at 70 ° C for 4 hours. At this time, the urethane reaction conditions are as follows: NCO content of prepolymer excluding filler is 10%, NCO / O
The H ratio was 5.1. Then cool down to room temperature and
400 parts by weight and 10 parts by weight of bis (2,6-dimethylmorpholinoethyl) ether were added to obtain a solvent-free 1-component moisture-curable urethane adhesive.

(Example 2) In the production process of Example 1, calcium carbonate having a viscosity ratio of DOP dispersion liquid of 2.5 was used as the surface-treated calcium carbonate (trade name Shiro Gloss CC;
Shiroishi Industry Co., Ltd.) was used, and the adhesive was obtained in the same manner as in Example 1 except for the above.

Example 3 In the production process of Example 1, calcium carbonate having a viscosity ratio of DOP dispersion liquid of 4.7 (trade name Calfine 100; manufactured by Maruo Calcium Co.) was used as the surface-treated calcium carbonate. An adhesive was obtained in the same manner as in Example 1 except for the above.

Example 4 In the manufacturing process of Example 3, rosin polyol (trade name KE-381; manufactured by Arakawa Chemical Co., Ltd.) was used in place of the hydroxyl group-containing xylene resin,
An adhesive was obtained in the same manner as in Example 3 except for the above.

Comparative Example 1 A 5 L planetary mixer (trade name Planetary Mixer PLM5; manufactured by Inoue Seisakusho) was previously dehydrated, and a bifunctional polypropylene glycol having a molecular weight of 2000 (trade name Takelac P-21; manufactured by Takeda Pharmaceutical Co., Ltd.) was used. ) 500 parts by weight, molecular weight 3000 trifunctional polypropylene glycol (trade name Takelac P-3
1, Takeda Pharmaceutical Company Limited) 100 parts by weight, molecular weight 2000
200 parts by weight of a bifunctional polyester polyol (trade name: ADEKA NEW ACE F7-67, manufactured by Asahi Denka Kogyo Co., Ltd.), and 200 parts by weight of a hydroxyl group-containing xylene resin (trade name: Nikanol H; manufactured by Mitsubishi Gas Chemical Co., Inc.). In addition, 591 parts by weight of a mixture in which 4,4′-MDI and 2,4′-MDI were present in half were added, and the urethanization reaction was carried out at 90 ° C. for 4 hours. The urethane reaction conditions at this time are NC
The O content was 10% and the NCO / OH ratio was 5.1.
After cooling to room temperature, an isocyanate-terminated prepolymer was once obtained. Next, 1000 parts by weight of dehydrated surface-untreated calcium carbonate (trade name NS100; manufactured by Nitto Koka Co., Ltd., sometimes abbreviated as "heavy carbon" hereinafter), D
OP 400 parts by weight was added, and further 10 parts by weight of bis (2,6-dimethylmorpholinoethyl) ether was added and mixed and processed to obtain a solvent-free 1-liquid moisture-curable urethane adhesive.

(Comparative Example 2) In the manufacturing process of Example 1, non-surface-treated calcium carbonate (trade name NS100; manufactured by Nitto Koka Co., Ltd.) was used in place of the surface-treated calcium carbonate. An adhesive was obtained in the same manner as in Example 1 except for the above.

(Comparative Example 3) In the manufacturing process of Comparative Example 1, surface-treated calcium carbonate (trade name Calfine 100;
Maruo Calcium Co., Ltd.) was used, and an adhesive was obtained in the same manner as in Comparative Example 1 except for that.

Examples 1, 2, 3, 4 and Comparative Examples 1, 2,
The formulation of 3 is shown in Table 1.

[0057]

[Table 1]

In Table 1, PPG: Takerak P21 PPG: Takerak P31 Polyester: ADEKA New Ace F7-67 Xylene resin: Nikanol H Rosin polyol: KE-381 Treated charcoal: Homocal DM Treated charcoal: Shiranka CC Treated charcoal: Calfine 100 Heavy coal: NS100 Is.

The coating liquid workability (viscosity and viscosity), adhesiveness, and initial tack (developing time and its width) of the thus obtained one-component moisture-curable urethane adhesive were evaluated by the following methods.

The coating workability (viscosity and viscosity) was evaluated by the viscosity and viscosity of the composition, that is, the thixotropic index (hereinafter referred to as "TI value"). That is, the rotational speed of a BH type rotational viscometer (trade name: Viscometer BH; manufactured by Tokimec Co.) 20 r / min and 2 r / m
The viscosity in (23 ° C.) was measured, and the TI value shown in Formula 1 was calculated.

[0061]

## EQU1 ## Viscosity at TI = 2r / min / 20r / m
viscosity in

The TI value serves as an index of good or bad coating workability, and a large value generally indicates good coating workability such as trowel separation, but it is absolutely dependent on the viscosity. Not a good indicator. Furthermore, the practical coating workability was evaluated by the lightness of troweling when actually coating with a comb-like iron. The evaluation was made into three grades of ◯, Δ and ×. ○
Means good, △ means good, × means not good, ○ means excellent, and △ feels that the trowel is heavy, but it is in a practical range, and × means that the trowel is too heavy and practically difficult to apply. .

Adhesiveness is determined by standard conditions (22 ± 1 ° C., 55 ±
Indoors adjusted to 5% RH), thickness 8mm, width 30m
m, 100 mm long flexible board, thickness 1.
A commercially available soft vinyl chloride sheet for flooring having a width of 5 mm, a width of 25 mm, and a length of 150 mm, and the above adhesive composition were left standing the day before, and the line was flexible so that the coating amount was about 250 g / m ² with a comb iron. After applying for 30 minutes to the board, the above PVC sheets are laminated and cured for 3 days under standard conditions, then the 90 degree peel strength is measured at a pulling speed of 50 mm / min, and the adhesive strength and fracture status are compared. did. If the breaking position is the adhesive layer, the adhesiveness to the adherend is good, but if the interface is between the adherend and the adhesive, it can be judged that the adhesiveness is poor.

The initial tack development time and the width of the initial tack were indoors adjusted to standard conditions (22 ± 1 ° C., 55 ± 5% RH), a flexible board with a thickness of 4 mm and a thickness of 1.5 m.
m, width 25 mm, length 150 mm, a commercially available soft PVC sheet for flooring, and the above adhesive composition were left unattended for the day before, and the lines were flexible so that the coating amount was about 250 g / m ² with a comb-like iron. Apply to the board, 10 minutes, 20 minutes, 30
After 40 minutes, 40 minutes, 50 minutes, and 60 minutes, the above PVC sheets were pasted together, and the initial tack when immediately peeled by hand, that is, the degree of tackiness of the adhesive film or the appearance of thread-like stickiness, and its resistance It was observed and evaluated in three grades of ◯, Δ, and ×. ◯ means good, Δ means good, × means bad, and Δ means that there is no problem in practical use, and ◯ means that a good initial cup is obtained.

The evaluation results of coating workability, adhesiveness and initial tack are shown in Table 2.

From the results shown in Table 2, although no viscosity modifier was added in any of the examples, the index T indicating the structural viscosity, which is the viscosity ratio of 2r / min and 20r / min, was obtained.
The I value was relatively large, and particularly in Examples 3 and 4, the coating workability with the comb-like iron was good. Regarding the adhesiveness, all of Examples 1 to 4 obtained by the one-step method using the surface-treated calcium carbonate show a high value, and breakage also occurs in the adhesive layer. Was excellent. Furthermore, the initial tack develops after about 20 minutes under standard conditions, and still retains a good tack after 60 minutes, and when the adherends are stuck together in that state, the adhesion of the adherends is good. It was

On the other hand, in Comparative Example 1, despite the low viscosity, the trowel separation was extremely poor and the coating workability was not practical. In Comparative Example 2, the same mixing ratio as in Comparative Example 1 was used, but the adhesiveness was somewhat improved as compared with Comparative Example 1 which is a two-step method, but other characteristics were the same as those in Comparative Example 1. At the same level, it is clearly inferior to the example. Comparative Example 3
Is an experiment by the two-step method with the same compounding ratio as in Example 3, but the coating workability is slightly improved as compared with Example 3, but the adhesiveness is reduced to half or less,
It has no practical value, such as not developing strong tack at all.

[0068]

[Table 2]

However, in Table 2, in the destroyed state,
A100 is 100% destruction of the adhesive layer. AF100 is 100 destruction of the interface between the adhesive layer and the adherend.
Indicates that it is%.

[0070]

As described above, the one-pack moisture-curing urethane adhesive of the present invention improves the adhesiveness and initial tack of the one-pack moisture-curing urethane adhesive obtained by the conventional two-step method. In addition, it is an adhesive that can impart excellent coating workability without adding a viscosity modifier and has a well-balanced performance required as an adhesive. With regard to the bonding work, it has a fast curing property, has a good bonding strength, and particularly exhibits excellent bonding properties to difficult-to-bond materials such as plastics. In addition, the early tack development is excellent.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08G 18/54 C08G 18/54 18/64 18/64 (56) Reference JP-A-11-181397 (JP, A) JP JP-A-9-235540 (JP, A) JP-A-8-199061 (JP, A) JP-A-3-62879 (JP, A) JP-A-8-239441 (JP, A) JP-A-9-137148 (JP , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C09J 4/00-201/10 C08G 18/00-18/87 C08L 23/00-101/16

Claims (5)

(57) [Claims] 1. An isocyanate-terminated urethane prepolymer obtained by reacting a polyol and an excess polyisocyanate in the presence of calcium carbonate, which has been surface-treated, with high adhesiveness, initial tack and coating work. A one-component moisture-curing urethane adhesive with excellent properties. 2. The surface-treated calcium carbonate according to claim 1, wherein the viscosity ratio at 28 ° C. when it is made into a dioctyl phthalate dispersion liquid of 15% by weight is 2.0 or more. A one-component moisture-curing urethane adhesive with the high adhesiveness described and excellent initial tack and coating workability. 3. The polyol according to claim 1 is composed of a mixture of a polyether polyol and a polyester polyol, and has high adhesiveness according to claim 1 or 2 and excellent in initial tack and coating workability. A one-pack moisture-curing urethane adhesive. 4. A high-adhesion and initial tack according to claim 3, wherein a xylene resin having a hydroxyl group and / or a rosin polyol is used as a part of the polyether polyol and the polyester polyol according to claim 3. And a one-component moisture-curing urethane adhesive with excellent coating workability. 5. The high-adhesive initial tack and coating workability according to claim 4, wherein the xylene resin according to claim 4 is an addition condensation oligomer of meta-xylene and formaldehyde and / or a modified product thereof. Excellent 1-liquid moisture-curing urethane adhesive.