JPH01174581A - Adhesive composition usable for long time - Google Patents

Abstract

PURPOSE:To obtain the above composition having excellent bond strength and a long pot life free from toxicity, by blending a specific prepolymer containing isocyanate group at the end with polypropylene glycol or polybutylene glycol as a curing agent. CONSTITUTION:(A) A prepolymer which contains polypropylene glycol, polytetramethylene glycol and/or polybutylene glycol component having 500-5,000mol.wt. and isocyanate group at the end is blended with (B) polypropylene glycol and/or polybutylene glycol having three or more ends containing tertiary hydroxyl groups and 300-6,000mol.wt. in an equivalent ratio of 0.8-1.1 hydroxyl group per isocyanate group of the component A to give the aimed composition.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an adhesive composition used for resin film lining inside piping, etc., and specifically, it has excellent adhesive strength,
This invention relates to an adhesive composition for a polyether type urethane film and a steel pipe that has a long pot life.

<Prior art and its problems> As a construction method for lining the inside of a pipe with a resin film, the existing pipeline is kept in its original state and the inside of the pipe is lined with a resin film, so that the pipe can be used for a long time. There is a construction method called the Restart construction method.

In this Restart construction method, as shown in FIG. 18, first, a plurality of pigs 2 are inserted into a pipe 1 with an adhesive 3 interposed between adjacent pigs 2. After that, water pressure is applied from the rear end of the pig 2 (from the right direction in the figure) using a liquid 4 such as water to move the pig 2 forward inside the pipe 1, thereby applying the adhesive 3 to the pipe wall 5 all around the circumference. .

Then, as shown in FIG. 1b, the cylindrical resin film 7 is inserted into the pipe by the restoring pig 8,
This is a method of lining the pipe 1 by closely adhering it to the pipe wall 5 of the pipe 1 using a resin film adhesive 3.

Conventionally, epoxy/polyamide amine-based adhesives have been used as adhesives for this type of construction, but because of their short pot life, the adhesive thickens, making it difficult for the pig to move. It cannot be used for long pipes of several thousand meters, and since it uses amine as a hardening agent, it cannot be used for water supply pipes either.

<Object of the invention> The present invention was made in view of the above circumstances, and an object thereof is to provide an adhesive composition that has a long pot life, has good adhesive strength, and is non-toxic. In particular, it can be used as a strong adhesive between polyether-type urethane film and steel pipes for resin film lining inside pipes.
Another object of the present invention is to provide an adhesive composition that is non-toxic and can be used as an adhesive for drinking water piping.

<Structure of the invention> That is, according to the present invention, the molecular weight is 500 to 5000
The prepolymer contains one or more of polypropylene glycol, polytetramethylene glycol, and polybutylene glycol, and has isocyanate groups at its terminals, and has at least three or more tertiary hydroxyl groups at its terminals, and has a molecular weight of 300 to 6,000 polypropylene glycol and/or polybutylene glycol so that the equivalent amount of hydroxyl groups per isocyanate group is 0.8 to 1.1 times, and has a long pot life. An adhesive composition is provided.

The adhesive composition of the present invention will be explained in detail below.

The prepolymers having isocyanate groups at the terminals used as the main component in the present invention include polypropylene glycol (PPG), polytetramethylene glycol (PPG), and polypropylene glycol (PPG).
TMG) or polybutylene glycol (PBG)
It is obtained by reacting one or more of these with a polyisocyanate compound.

The polypropylene glycol, polytetramethylene glycol or polybutylene glycol used here preferably has a molecular weight in the range of 500 to 5000, respectively.

The reason is that if the molecular weight is less than 500, the reactivity will be high and the pot life will be shortened.
This is because when it exceeds 5,000, the reactivity decreases and hardening does not occur.

The polyisocyanate compound used in the present invention is a compound having two or more isocyanate groups in the molecule,
Those used in the production of ordinary polyurethane resins can be used, such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, triphenylmethane triisocyanate, and the like.

Polypropylene glycol (PPG) or polybutylene glycol (PBG) used as a curing agent in the adhesive composition of the present invention has at least three or more terminal tertiary hydroxyl groups.

By having three or more hydroxyl groups, the hardness of the cured adhesive increases and the adhesive strength increases. Furthermore, this hydroxyl group is
Because it is tertiary, the reaction is slow and the pot life can be maintained for a long time.

Further, the polypropylene glycol and polybutylene glycol used here preferably have a molecular weight in the range of 300 to 6,000, more preferably 500 to 2,000.
The range is 000. This is because if the molecular weight is less than 3QO, the pot life will be shortened due to high reactivity.
On the other hand, if it exceeds 6000, the reactivity will be slow and curing failure will occur.

The blending amount of the prepolymer with isocyanate groups at the terminals used as the main ingredient in the wood invention and the curing agent polypropylene glycol and/or soybean or polybutylene glycol is 0.8 hydroxyl groups per isocyanate group.
It is preferable to mix in the range of ~1.1 times equivalent, because if it is less than 0.8 times equivalent, the adhesive force will be poor, whereas if it exceeds 1.1 times equivalent, curing will be sufficient. This is because it is not done.

In the present invention, various solvents and fillers can be appropriately added to the adhesive composition. For example, aromatic hydrocarbons such as benzene, toluene, and xylene, and aliphatic hydrocarbons such as n-offdan can be mixed as solvents to adjust viscosity and reduce costs. It is also possible to mix an inorganic filler such as calcium carbonate or clay as a filler.

<Examples> The present invention will be described in more detail below based on examples.

[Example 1] Polypropylene glycol (hydroxyl value 34.3, molecular weight 4900, Hyflex G-500
After adding 9.6 g of tolylene diisocyanate (TDI80; manufactured by Kasei Upjimen Co., Ltd.) under a nitrogen atmosphere and stirring, 0.1 g of dibutyltin silaurylate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) and heat at 80℃ for 5 minutes.
The reaction was carried out for a period of time to obtain a prepolymer having isocyanate groups at the ends. An equivalent amount of trifunctional polybutylene glycol (hydroxyl value 548, molecular weight 307, H-4698, Dai-Kogyo Seiyaku) with a tertiary terminal was mixed into this prepolymer to prepare an adhesive.

Using this adhesive', an adhesion test and a pot life measurement were conducted in the manner described below to evaluate the quality.

Quality evaluation> ■ Adhesion test 0.4 mm thick polyether type urethane film with polytetramethylene glycol skeleton and steel plate (5PCC-SB)
; made by Nippon Test Panel).

The surfaces of the urethane film and steel plate were wiped with methanol before use, and the steel plate was further subjected to blasting using sandpaper (No. 60).

Apply the adhesive to the steel plate side with a bar coater to a thickness of 100 μm, attach the urethane film, and press it with a clip.
After being left at room temperature for two weeks, an adhesive force measurement test was conducted.

The adhesive strength was measured at 25° C. under the conditions of a peel angle of 180 degrees and a peel rate of 200 am/win.

■ Pot life isocyanate prepolymer and polyol mixture 5
0g was left in a constant temperature bath at 20°C, and the viscosity was measured over time using an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd.), and the time when the viscosity reached twice the initial viscosity was defined as the pot life.

Table 1 shows the blending amount, adhesion test results, and pot life.

(Examples 2 to 5) Polytetramethylene glycol (hydroxyl value 56, molecular weight 2000, PTMG2000; manufactured by Mitsubishi Chemical Industries) 85
．． 1g, polytetramethylene glycol (hydroxyl value 13
2. Molecular weight aSO1PTMG850, manufactured by Mitsubishi Chemical Industries) 70.9g, polypropylene glycol (hydroxyl value 5
6. Molecular weight 2000, Efcenol 2020: Asahi Glass) 85.1g, polybutylene glycol (hydroxyl value 5)
8. Molecular weight 1935, PBG2000; Dai-Kogyo Seiyaku) 85.1 g, 29, Og, 14.8 g, 14.8 g of tolylene diisocyanate were added under nitrogen atmosphere, stirred, and then carried out. The reaction was carried out in the same manner as in Example 1 to obtain a prepolymer having isocyanate groups at the ends. This prepolymer was added to the same trifunctional and tertiary-terminated polybutylene glycol (hydroxyl value 54) as in Example 1.
8, molecular weight 307) were added in equivalent amounts to Examples 2, 3, 4, and 5, respectively.

These were subjected to nine adhesion tests and pot life measurements in the same manner as in Example 1, and the results are shown in Table 1.

[Examples 6 and 7] 20.0 g of diphenylmethane-4,4'-diisocyanate (Millionate MT, manufactured by Nippon Polyurethane Co., Ltd.) was added to 79.9 g and 85.6 g of polytetramethylene glycol (hydroxyl value 56, molecular weight 2000), respectively. After adding 14.3 g of hexamethylene diisocyanate (manufactured by Difumodur H1, manufactured by Bayer Urethane AG) under a nitrogen atmosphere and stirring, the mixture was reacted in the same manner as in Example 1 to obtain a prepolymer having isocyanate groups at the ends. This prepolymer was added to the same trifunctional, tertiary-terminated polybutylene glycol as in Example 1 (hydroxyl value 548, molecular weight 307).
) was added in an equivalent amount, and the adhesion test and pot life measurement were conducted in the same manner as in Example 1. The results are shown in Table 1.

[Example 8] Tolylene diisocyanate 14 to 85.1 g of polytetramethylene glycol (hydroxyl value 56, molecular weight 2000)
．． After adding and stirring 8 g under a nitrogen atmosphere, the reaction was carried out in the same manner as in Example 1 to obtain a prepolymer having isocyanate groups at the ends. Furthermore, trifunctional polybutylene glycol (hydroxyl value 32) is added to this prepolymer.
, molecular weight 5260, H-4696, Dai-Kogyo Seiyaku) was added thereto, and the adhesion test and pot life measurement were conducted in the same manner as in Example 1. The results are shown in Table 1.

[Examples 9 to 11] Tolylene diisocyanate 14 to 85.1 g of polytetramethylene glycol (hydroxyl value 56, molecular weight 2000)
．． After adding and stirring 8 g under a nitrogen atmosphere, the reaction was carried out in the same manner as in Example 1 to obtain a prepolymer having isocyanate groups at the ends. To this prepolymer, trifunctional and tertiary-terminated polybutylene glycol (hydroxyl value 548, molecular weight 307) was added in an equivalent amount of 0.8.1.0.1.1, respectively.
Examples 9, 10 and 11 were obtained by adding twice as much.

These were subjected to an adhesion test and pot life measurements in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1) Hexamethylene diisocyanate 29 was added to 70.1 g of aliphatic polyester polyol (hydroxyl value: 142, molecular weight: 790, 60%, manufactured by Sumitomo Bayer Urethane).
．． After adding and stirring 8 g under a nitrogen atmosphere, the reaction was carried out in the same manner as in Example 1, and an equivalent amount of the same polybutylene glycol (hydroxyl value 548) as in Example 1 was added thereto. This was subjected to an adhesion test and pot life measurement in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2) Tolylene diisocyanate 1 to 85.1 g of polytetramethylene glycol (hydroxyl value 56, molecular weight 2000)
After adding 4.8 g under nitrogen atmosphere and stirring, Example 1
The reaction was carried out in the same manner as above, and an equivalent amount of polybutylene glycol (hydroxyl value 436, molecular weight 386, H-4697; Dai-Kogyo Seiyaku) having a trifunctional terminal and a secondary hydroxyl group was added thereto. This was subjected to an adhesion test and pot life measurement in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3] Tolylene diisocyanate 14 was added to 85.1 g of polytetramethylene glycol (hydroxyl value 56, molecular weight 2000).
．． After adding and stirring 8 g under a nitrogen atmosphere, the reaction was carried out in the same manner as in Example 1.
8.8, molecular weight 1935, PBG 2000; Dai-Kogyo Seiyaku) was added in an equivalent amount. This was subjected to the same adhesion test and pot life measurement as in Example 1. The results are shown in Table 1.

(Comparative Example 4) Adhesion tests and pot life measurements were conducted in the same manner as in Example 1 using a general-purpose epoxy resin/polyamide amine adhesive. The results are shown in Table 1.

, (Comparative Example 5.6) Tolylene diisocyanate 14 to 85.1 g of polytetramethylene glycol (hydroxyl value 56, molecular weight 2000)
．． After adding and stirring 8 g under a nitrogen atmosphere, the reaction was carried out in the same manner as in Example 1, and to this was added trifunctional polybutylene glycol (hydroxyl value 548, molecular weight 30), which had a tertiary terminal.
Comparative Example 5: Added 0.5 and 1.5 times the equivalent amount, respectively.
．． It was set at 6. These were subjected to an adhesion test and pot life measurements in the same manner as in Example 1. The results are shown in Table 1.

As is clear from Table 1, it can be seen that in the Examples, the adhesive strength is improved and the pot life is extended.

On the other hand, in all of the comparative examples, the adhesive strength was reduced or the pot life was only short, and there were no products with high adhesive strength and long pot life as seen in the examples.

<Effects of the Invention> As detailed above, the adhesive composition obtained by the present invention is a polypropylene glycol having at least three or more tertiary hydroxyl groups or a polybutylene glycol having an isocyanate group at the end. By using the polymer as a curing agent, the adhesive strength was increased compared to conventional products, and the pot life was also extended.

Furthermore, since this adhesive composition does not contain amines, it has the advantage that it can also be used for water supply piping.

Therefore, urethane-based adhesives originally had problems such as slow curing and sagging when applied to walls, etc., but when used for lining steel pipes with resin film as in this application, Since a particularly long pot life is required for lining long pipes, such as several thousand meters, at a time, the adhesive composition having a long pot life according to the present invention can be applied. Also, since the steel pipe and film are in close contact, there is no problem with sagging.

[Brief explanation of the drawing]

FIGS. 1a and 1b are sectional views for explaining the resin film lining inside the pipe. Explanation of symbols 1... Piping, 2... Pig, 3... Adhesive, 4... Liquid □, 5... Pipe wall, 7... Resin film, 8... Restart pigpa, '1:・,, ,,:,':,-1 FIG, la FIG, 1b

Claims (1)

[Claims] (1) A prepolymer containing one or more of polypropylene glycol, polytetramethylene glycol, and polybutylene glycol having a molecular weight of 500 to 5,000 and having isocyanate groups at its terminals has at least three terminals. It has a hydroxyl group of 300% and has a molecular weight of 300.
An adhesive having a long pot life characterized by being made by mixing polypropylene glycol and/or polybutylene glycol of 6,000 to 0.8 to 1.1 equivalents of hydroxyl groups per isocyanate group. Composition.