JP2005247983A - Cleaning agent for moisture-curable urethane adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning agent for a coater for a moisture-curable urethane adhesive, which agent is a solid at ordinary temperature, the residue of which can easily be removed by cooling the equipment after the cleaning, which enables the work of displacing with the adhesive to be completed in a short time, and which does not cause reactions in the equipment and hardly causes deficiencies such as deterioration and foaming. <P>SOLUTION: The cleaning agent contains 20-80 pts. wt. of a vinyl polymer (A) which is a solid at ordinary temperature and has a mol. wt. of 2,000-100,000, a softening point of 40-120°C, and no functional group reacting with an isocyanate group and 80-20 pts. wt. of an ester compound (B) which is a solid at ordinary temperature and has a softening point of 40-120°C and no functional group reacting with an isocyanate group. The cleaning agent has a viscosity of 100-10,000 mPa s at 120°C. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cleaning agent for moisture-curing urethane adhesives.

  Moisture-curing urethane adhesives, especially moisture-curing urethane hot-melt adhesives that are solid at room temperature, are one-component, convenient, solvent-free, easy to work with, and capable of high-speed adhesion, and heat resistance It is widely used for various applications because it has advantages such as excellent properties.

  Such a moisture curable urethane adhesive is generally applied by a coating machine such as a slit coater, a die coater, or a nozzle gun. For example, Patent Document 1 discloses a method for applying a moisture-curable hot melt adhesive made of a urethane prepolymer having an isocyanate group using a heated roll coater as a method for manufacturing a honeycomb sandwich structure panel.

  However, when the moisture curable urethane adhesive is applied with an adhesive applicator, a small amount of the moisture curable urethane adhesive remaining after application is adhered near the application port of the applicator. Inevitable. Even if such residual adhesive is extremely small in one application operation, it gradually increases as the application operation is repeated. There was a problem that the function of the mouth was impaired.

  As a method for solving these problems, Patent Document 2 adds a compound having a functional group capable of reacting with an isocyanate group in the molecule before the moisture-curing urethane-based adhesive attached to the coating machine is cured. A method for removing an adhesive including a mixing step is disclosed.

JP-A-2-258243 JP-A-6-240212

  However, the above-described conventional method is a preferable method when a roll coater whose entire coating portion is an open type is used as a coating machine, but a coating machine whose coater head portion is not an open type such as a die coater or a slit coater. There was a problem that could not be used for cleaning.

  Further, since the compound to be added and mixed contains a liquid component, it is difficult to remove the residue after washing. Furthermore, since the high molecular weight compound is not added to the above compound, it is difficult to adjust the viscosity after melting, resulting in a very low viscosity, and it is difficult to remove the moisture-curable urethane adhesive remaining on the bottom of the applicator tank or the hose. There was a problem such as.

  Therefore, in view of the above problems, the problem to be solved by the present invention is solid at room temperature, the residue can be easily removed by cooling the apparatus after washing, and the work of replacing with an adhesive is also possible. An object of the present invention is to provide a cleaning agent for a moisture-curing urethane-based adhesive applicator that can be completed in a short time and does not react in the apparatus, and is less likely to cause defects such as alteration and foaming.

The moisture curable urethane adhesive cleaning agent of the present invention has a molecular weight of 2000 to 100000, a softening point of 40 to 120 ° C., and a room temperature solid vinyl polymer (A) 20 to 20 having no functional group that reacts with an isocyanate group. Contains 80 to 20 parts by weight of a normal temperature solid ester compound (B) having a functional group that reacts with an isocyanate group at 80 parts by weight and a softening point of 40 to 120 ° C., and a viscosity at 120 ° C. of 100 to 10,000 mPa · s. It is characterized by being.
The present invention is described in detail below.

  Although it does not specifically limit as a normal temperature solid vinyl polymer (A) which does not have the functional group which reacts with the isocyanate group used by this invention, For example, copolymers, such as an acrylate monomer, a styrene monomer, an acrylonitrile monomer, are mentioned Among them, those having good compatibility with the moisture-curing urethane adhesive are preferably used.

  The normal temperature solid vinyl polymer (A) having no functional group that reacts with the isocyanate group has a molecular weight of 2000 to 100000 in order to give a melt viscosity suitable for the cleaning agent of the moisture-curing urethane adhesive of the present invention. It is limited to. If the molecular weight is less than 2,000, the melt viscosity becomes very low and it becomes difficult to apply pressure for discharging from the applicator tank. Conversely, if the molecular weight exceeds 100,000, the resulting moisture-curing urethane adhesive cleaning agent melts. Viscosity becomes very high and ejection properties are poor.

Moreover, the normal temperature solid vinyl polymer (A) which does not have a functional group which reacts with the isocyanate group is limited to a softening point of 40 to 120 ° C. If the softening point is less than 40 ° C., tack or the like is likely to occur, and workability deteriorates. Conversely, if the softening point exceeds 120 ° C., the cleaning agent becomes difficult to melt at the temperature at which the adhesive melts.
Here, the softening point means a softening point measured by a RandB (ring and ball) method.

  In the cleaning agent for the moisture curable urethane adhesive of the present invention, 20 to 80 parts by weight of the normal temperature solid vinyl polymer (A) having no functional group that reacts with the isocyanate group is contained. If the content of the vinyl polymer (A) is less than 20 parts by weight, the viscosity becomes too low to make gear pump extrusion difficult. Conversely, if the content exceeds 80 parts by weight, the viscosity becomes too high and extrusion is difficult. It becomes.

  The room temperature solid ester compound (B) having no functional group that reacts with the isocyanate group used in the present invention is compatible with the room temperature solid vinyl polymer (A) having no functional group that reacts with the isocyanate group. For example, ethylene glycol fatty acid ester, ethylene glycol aromatic acid ester, propylene glycol fatty acid ester, propylene glycol aromatic acid ester, polyester terminal esterified compound and the like can be mentioned.

  The normal temperature solid ester compound (B) having no functional group that reacts with the isocyanate group is limited to a softening point of 40 to 120 ° C. If the softening point is less than 40 ° C., the viscosity becomes too low and gear pump extrusion becomes difficult. Conversely, if the softening point exceeds 120 ° C., the viscosity becomes too high and extrusion becomes difficult.

  In the cleaning agent for the moisture curable urethane adhesive of the present invention, the normal temperature solid ester compound (B) having no functional group that reacts with the isocyanate group is contained in an amount of 80 to 20 parts by weight. If the content of the ester compound (B) exceeds 80 parts by weight, tackiness is likely to occur, and workability deteriorates. Conversely, if the content is less than 20 parts by weight, the cleaning agent is used at the temperature at which the adhesive melts. It becomes difficult to melt.

  The moisture curable urethane-based adhesive cleaning agent of the present invention has a viscosity at 120 ° C. of 100 to 10,000 mPa · s. When the viscosity at 120 ° C. is less than 100 mPa · s, a sufficient pressure cannot be applied, so that the cleaning effect is deteriorated. On the other hand, when the viscosity exceeds 10000 mPa · s, removal from the coating machine becomes difficult.

  In the present invention, the functional group that reacts with the isocyanate group includes an amino group, a urethane group, a hydroxyl group, and the like, and means a functional group that reacts with the isocyanate group at room temperature and when melted.

  As a method for cleaning the adhesive applicator using the moisture curable urethane adhesive cleaning agent of the present invention, the present invention is applied to the melting port of the adhesive applicator after the moisture curable urethane adhesive is applied. This can be done by introducing the cleaning agent of the invention.

  The cleaning agent for the moisture-curing urethane adhesive of the present invention is configured as described above, and since it is a solid at room temperature, the residue can be easily removed by cooling the device after cleaning, and it is bonded after cleaning. The operation of substituting with the agent can be completed in a short time, and further, since there is no reaction in the apparatus, there is little possibility of problems such as alteration and foaming.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1)
Normal temperature solid ester polymer (B) in 50 parts by weight of acrylic acid ester-styrene copolymer (ARUFON UP-1100 manufactured by Toagosei Co., Ltd.) having a molecular weight of 8000 and a softening point of ° C as a normal temperature solid vinyl polymer (A) 50 parts by weight of “Unistar E275” manufactured by NOF Corporation having a softening point of 40 to 120 ° C. was added and melt-kneaded at 120 ° C. to obtain a cleaning agent for moisture-curing urethane adhesive. The viscosity at 120 ° C. was 500 mPa · s.

(Example 2)
Washing of moisture-curing urethane adhesive in the same manner as in Example 1 except that 80 parts by weight of “ARUFON UP-1100” manufactured by Toagosei Co., Ltd. and 20 parts by weight of “Unistar E275” manufactured by NOF Corporation are used. An agent was obtained. The viscosity at 120 ° C. was 2000 mPa · s.

(Example 3)
Softening as a normal temperature solid ester compound (B) in 50 parts by weight of a styrene polymer having a molecular weight of 2800 and a softening point of 40 to 120 ° C. (“ARUFON XF-900” manufactured by Toagosei Co., Ltd.) as a normal temperature solid vinyl polymer (A) A 50 ° part of “Nonion DS-60H” manufactured by Nippon Oil & Fats Co., Ltd. was added and melt-kneaded at 120 ° C. to obtain a cleaning agent for moisture-curing urethane adhesive. The viscosity at 120 ° C. was 200 mPa · s.

(Comparative Example 1)
An acrylic ester-styrene copolymer ("ARUFON UP-1100" manufactured by Toagosei Co., Ltd.) alone having a molecular weight of 8000 and a softening point of more than 120 ° C as a room temperature solid vinyl polymer (A) is a moisture curable urethane adhesive. Used as a cleaning agent. The viscosity at 120 ° C. exceeded 100,000 mPa · s.

(Comparative Example 2)
As a normal temperature solid ester compound (B), “Nonion DS-60H” alone, which has a softening point of less than 40 ° C., was used as a cleaning agent for a moisture-curing urethane adhesive. The viscosity at 120 ° C. was less than 100 mPa · s.

(Performance evaluation)
Using a reactive hot melt applicator (“MC12” manufactured by Nordson), 2.5 kg of moisture-curing urethane adhesive (“Sdyne 9611B” manufactured by Sekisui Chemical Co., Ltd.) was melted at 100 ° C. and used. The adhesive was extracted, and about 5 kg of the cleaning agent obtained in each of the above Examples and Comparative Examples was put into an applicator and left at 100 ° C. for about 2 hours. Then, after discharging the cleaning agent, the amount of adhesive remaining on the bottom of the applicator was visually confirmed to evaluate the cleaning effect.

-Evaluation of viscosity It measured by rotor No4 and rotation speed 12rpm using the rotation type B type viscometer.

・ Evaluation of ejection performance When ejected at a speed of 60 rpm, the state of scattering due to low viscosity is “× scattering”, the state of difficulty in ejection due to high viscosity is “× ejection impossible”, and moisture-curing urethane adhesive The case where ejection was possible while being compatible or swollen was evaluated as “◯”.

-Evaluation of detergency The total amount of adhesive remaining on the bottom of the applicator was visually confirmed, and evaluated as "× many" and "small ○".

  The performance of the cleaning agents of the moisture curable urethane adhesives obtained in Examples 1 to 3 and Comparative Examples 1 and 2 was evaluated by the above method. The results are shown in Table 1.

As is apparent from Table 1, the cleaning agents of the examples of the present invention have a high cleaning effect due to high compatibility with moisture-curing urethane adhesives, and also have good discharge properties due to having an appropriate viscosity. Thus, a high cleaning effect was obtained in a short time. On the other hand, Comparative Example 1 was not sufficiently compatible with the adhesive and the melt viscosity was too high, so that a sufficient cleaning effect was not obtained, and the discharging time was very long and the workability was poor. In Comparative Example 2, the compatibility with the moisture curable urethane-based adhesive was very good, but since the melt viscosity was too low, the dischargeability was poor and the workability was poor.

Claims (1)

An isocyanate group having a molecular weight of 2,000 to 100,000, a softening point of 40 to 120 ° C., a normal temperature solid vinyl polymer (A) having no functional group that reacts with an isocyanate group (A) 20 to 80 parts by weight, and a softening point of 40 to 120 ° C. A moisture-curing urethane-based adhesive comprising 80 to 20 parts by weight of a normal temperature solid ester compound (B) having no functional group that reacts with the water and having a viscosity at 120 ° C. of 100 to 10,000 mPa · s. Washing soap.