Catalyst, copolyester hot melt adhesive with low VOC emission and preparation method of copolyester hot melt adhesive

Abstract

The invention belongs to the technical field of polyester hot melt adhesives, and discloses a catalyst, a copolyester hot melt adhesive with low VOC emission and a preparation method of the copolyester hot melt adhesive. The catalyst is prepared by mixing and reacting dihydric alcohol and tetrabutyl titanate. The preparation method of the copolyester hot melt adhesive with low VOC emission comprises the following steps: mixing the copolyester hot melt adhesive with the catalyst, carrying out esterification reaction, and carrying out reduced pressure polycondensation reaction after the esterification reaction is finished, thereby obtaining the copolyester hot melt adhesive with low VOC emission. The invention provides a synthesis method of a low-VOC (volatile organic compound) copolyester hot melt adhesive, copolyester is produced and synthesized through a self-made catalyst on the basis of copolyester hot melt gluing, and the catalyst is a chelate of tetrabutyl titanate and dihydric alcohol.

Description

Technical Field

[0001] The invention relates to the technical field of polyester hot melt adhesives, and in particular to a catalyst, a copolyester hot melt adhesive with low VOC emission and a preparation method thereof. Background Art

[0002] Hot melt adhesive is solid at room temperature. It is melted by heating and adheres to the adherend. After cooling, it forms an adhesive with a certain adhesive strength. Hot melt adhesive is a solvent-free, non-toxic adhesive with 100% solid content.

[0003] Hot melt adhesive is widely used in textile, automobile and other industries. Car interior, seats, coat racks and other fabrics and leather are now basically bonded and laminated with hot melt adhesive. Due to environmental factors and the improvement of quality of life, the VOC requirements in car interiors are becoming more and more stringent. The VOC in car interiors mainly comes from the materials used in the car and its various auxiliary materials. Hot melt adhesive is one of the auxiliary materials - adhesive.

[0004] Therefore, how to reduce the VOC of hot melt adhesive is an urgent problem that needs to be solved. Summary of the invention

[0005] The object of the present invention is to provide a catalyst, a copolyester hot melt adhesive with low VOC emission and a preparation method thereof, so as to solve the problem of high VOC emission of existing hot melt adhesives.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a catalyst, comprising the following steps:

[0008] The diol and tetrabutyl titanate are mixed and reacted to obtain a catalyst.

[0009] Preferably, in the above-mentioned method for preparing a catalyst, the diol is two or more of ethylene glycol, 1,4-butanediol, 1,3-propylene glycol, and polypropylene glycol 2000;

[0010] The mass of the 1,4-butanediol is 0 to 30% of the mass of the ethylene glycol;

[0011] The mass of the 1,3-propylene glycol is 25 to 40% of the mass of the ethylene glycol;

[0012] The mass of the polypropylene glycol 2000 is 5-20% of the mass of ethylene glycol.

[0013] Preferably, in the above-mentioned method for preparing a catalyst, the mass of the tetrabutyl titanate is 30-50% of the mass of the diol.

[0014] Preferably, in the above-mentioned method for preparing a catalyst, the reaction temperature is 145-150° C., and the reaction time is 4-6 hours.

[0015] The invention also provides a catalyst prepared by the catalyst preparation method.

[0016] The present invention also provides a method for preparing a copolyester hot melt adhesive with low VOC emission, comprising the following steps:

[0017] The copolyester hot melt adhesive is mixed with the above catalyst to carry out esterification reaction, and after the esterification reaction is completed, a reduced pressure polyurethane reaction is carried out to obtain a copolyester hot melt adhesive with low VOC emission.

[0018] Preferably, in the above method for preparing a copolyester hot melt adhesive with low VOC emission, the mass of the catalyst is 0.08-0.15% of the mass of the copolyester hot melt adhesive.

[0019] Preferably, in the above-mentioned method for preparing a copolyester hot melt adhesive with low VOC emission, the temperature of the esterification reaction is 170-225°C;

[0020] When the amount of water distilled from the esterification reaction is more than 98% of the theoretical water output, the esterification reaction is completed.

[0021] Preferably, in the above method for preparing a copolyester hot melt adhesive with low VOC emission, the conditions for the reduced pressure polyurethane reaction are: pressure of 30-50 Pa, temperature of 250-255° C., and time of 2-5 h.

[0022] The present invention also provides a method for preparing a copolyester hot melt adhesive with low VOC emission, and obtains the copolyester hot melt adhesive with low VOC emission.

[0023] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0024] The invention provides a method for synthesizing a low-VOC copolyester hot melt adhesive. The method adopts the synthesis of the copolyester hot melt adhesive as a basis, and produces and synthesizes the copolyester by using a self-made catalyst. The catalyst is a chelate of tetrabutyl titanate and a diol, which improves the hydrolysis stability of the catalyst, thereby improving the conversion rate of the esterification reaction, and narrowing the molecular weight distribution of the polymerization during the polymerization reaction; thereby overcoming the problem that the conventional tetrabutyl titanate is easy to hydrolyze. DETAILED DESCRIPTION

[0025] The present invention provides a method for preparing a catalyst, comprising the following steps:

[0026] The diol and tetrabutyl titanate are mixed and reacted to obtain a catalyst.

[0027] In the present invention, the diol is preferably two or more of ethylene glycol, 1,4-butanediol, 1,3-propylene glycol, and polypropylene glycol 2000.

[0028] In the present invention, the mass of the 1,4-butanediol is preferably 0 to 30% of the mass of the ethylene glycol, more preferably 2 to 25%, and even more preferably 10 to 20%.

[0029] In the present invention, the mass of the 1,3-propylene glycol is preferably 25 to 40% of the mass of the ethylene glycol, more preferably 28 to 38%, and even more preferably 30 to 35%.

[0030] In the present invention, the mass of the polypropylene glycol 2000 is preferably 5 to 20% of the mass of the ethylene glycol, more preferably 10 to 18%, and even more preferably 12.5 to 15%.

[0031] In the present invention, the mass of the tetrabutyl titanate is preferably 30 to 50% of the mass of the diol, more preferably 32.88 to 40%, and even more preferably 37.04 to 38.71%.

[0032] In the present invention, the process of mixing the diol and tetrabutyl titanate is:

[0033] After the diol was heated to 110°C, tetrabutyl titanate was added.

[0034] In the present invention, the reaction temperature is preferably 145-150°C, more preferably 146-149°C, more preferably 147-148°C; the reaction time is preferably 4-6h, more preferably 4.5-5.5h, more preferably 5h.

[0035] In the present invention, after the reaction is completed, the step further includes: cooling at room temperature.

[0036] The invention also provides a catalyst prepared by the catalyst preparation method.

[0037] The present invention also provides a method for preparing a copolyester hot melt adhesive with low VOC emission, comprising the following steps:

[0038] The copolyester hot melt adhesive is mixed with the above catalyst to carry out esterification reaction, and after the esterification reaction is completed, a reduced pressure polyurethane reaction is carried out to obtain a copolyester hot melt adhesive with low VOC emission.

[0039] In the present invention, the copolyester hot melt adhesive is preferably the copolyester hot melt adhesive G-3 produced by Nantong Xinxing.

[0040] In the present invention, the mass of the catalyst is preferably 0.08-0.15% of the mass of the copolyester hot melt adhesive, more preferably 0.09-0.14%, and even more preferably 0.1-0.12%.

[0041] In the present invention, the temperature of the esterification reaction is preferably 170 to 225°C, more preferably 175 to 210°C, and more preferably 180 to 200°C;

[0042] When the amount of water distilled from the esterification reaction is more than 98% of the theoretical water output, the esterification reaction is completed.

[0043] In the present invention, the conditions for the reduced pressure polyurethane reaction are: the pressure is preferably 30-50 Pa, more preferably 35-48 Pa, more preferably 40-45 Pa; the temperature is preferably 250-255° C., more preferably 251-254° C., more preferably 252-253° C.; the time is preferably 2-5 h, more preferably 2-4 h, more preferably 2-3 h.

[0044] The present invention also provides a method for preparing a copolyester hot melt adhesive with low VOC emission, and obtains the copolyester hot melt adhesive with low VOC emission.

[0045] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] Example 1

[0047] According to the ingredients and reaction conditions in Table 1, diol was added into a stirred reactor, stirring was started and the temperature was raised to 110°C at 0.5°C / min, and then tetrabutyl titanate was added into the reactor, and the temperature was continued to be raised to 145-150°C, and the reaction was carried out for 4.0-6.0 hours. After cooling at room temperature, catalysts A1-A6 were obtained (catalyst A6 was a comparative catalyst, and catalysts A1-A5 were implemented catalysts).

[0048] Table 1 Catalyst ingredients

[0049]

[0050]

[0051] Example 2

[0052] According to the ingredients in Table 2, copolyester hot melt adhesive G-3 (Nantong Xinxing) and catalysts A1 to A6 prepared in Example 1 were added to the esterification kettle for esterification reaction, the reaction temperature was 170°C to 225°C, and the esterification reaction was completed when the amount of distilled water in the esterification reaction was more than 98% of the theoretical water output; the reduced pressure polycondensation reaction was carried out at 250 to 255°C and 30 to 50Pa for 2.0 hours to obtain a copolyester hot melt adhesive G-3 product with low VOC emissions. The obtained copolyester hot melt adhesive G-3 product with low VOC emissions was tested for VOC according to the standard GB / T 33372-2020, and the test results are shown in Table 2.

[0053] Table 2 Ingredients of low VOC emission copolyester hot melt adhesive G-3 and VOC test results

[0054]

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a catalyst, characterized in that: The following steps are involved: The diol and tetrabutyl titanate are mixed and reacted to obtain a catalyst.

2. The method for preparing a catalyst according to claim 1, characterized in that: The diol is two or more of ethylene glycol, 1,4-butanediol, 1,3-propylene glycol, and polypropylene glycol 2000; The mass of the 1,4-butanediol is 0 to 30% of the mass of the ethylene glycol; The mass of the 1,3-propylene glycol is 25 to 40% of the mass of the ethylene glycol; The mass of the polypropylene glycol 2000 is 5-20% of the mass of ethylene glycol.

3. The method for preparing the catalyst according to claim 2, characterized in that: The mass of the tetrabutyl titanate is 30-50% of the mass of the diol.

4. The method for preparing the catalyst according to claim 3, characterized in that: The reaction temperature is 145-150° C., and the reaction time is 4-6 hours.

5. A catalyst obtained by the method for preparing a catalyst according to any one of claims 1 to 4.

6. A method for preparing a copolyester hot melt adhesive with low VOC emission, characterized in that: The following steps are involved: The copolyester hot melt adhesive is mixed with the catalyst described in claim 5, and an esterification reaction is carried out. After the esterification reaction is completed, a reduced pressure polyurethane reaction is carried out to obtain a copolyester hot melt adhesive with low VOC emission.

7. The method for preparing a copolyester hot melt adhesive with low VOC emission according to claim 6, characterized in that: The mass of the catalyst is 0.08-0.15% of the mass of the copolyester hot melt adhesive.

8. The method for preparing a copolyester hot melt adhesive with low VOC emission according to claim 6, characterized in that: The temperature of the esterification reaction is 170-225°C; When the amount of water distilled from the esterification reaction is more than 98% of the theoretical water output, the esterification reaction is completed.

9. The method for preparing a copolyester hot melt adhesive with low VOC emission according to claim 8, characterized in that: The conditions of the reduced pressure polycondensation reaction are as follows: pressure of 30-50 Pa, temperature of 250-255° C., and time of 2-5 h.

10. The copolyester hot melt adhesive with low VOC emission obtained by the method for preparing the copolyester hot melt adhesive with low VOC emission according to any one of claims 6 to 9.

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