CN102690409B - Method for preparing low-melting-point polyester hot melt adhesive - Google Patents

Abstract

The invention discloses a method for preparing a low-melting copolyester hot-melt adhesive, which mainly includes the following steps: (1) esterification reaction of dodecanedioic acid and C ₂ -C ₄ glycol under the action of a catalyst; ( 2) Add aliphatic dibasic acid, diethylene glycol, neopentyl glycol and stabilizer to the product of step (1), carry out polycondensation under the pressure of 100-150Pa, keep the reaction temperature at 260-270°C, and the reaction time is 1 - After 2 hours, a copolyester hot melt adhesive product can be obtained; the copolyester has the characteristics of fast crystallization, low melting point, and not easy to be bonded to each other, and is suitable for use as an omentum adhesive material.

Description

A kind of preparation method of low melting point polyester hot melt adhesive

technical field

The invention relates to a polyester hot-melt adhesive and a manufacturing method thereof, in particular to a synthesis method of a polyester hot-melt adhesive based on polymer organic synthesis. the

Background technique

Polyester hot melt adhesive has a wide range of uses. The polyester resin used as hot melt adhesive is a thermoplastic product obtained by esterification of dibasic acid and diol. It is usually made of dimethyl terephthalate, isophthalic acid, ethylene glycol and butanediol, etc. as raw materials. For example, Chinese patent CN100439466C provides a kind of transesterification by dimethyl terephthalate and aliphatic diol, and then carries out polycondensation reaction, and its operation is simple and easy, but its curing speed is relatively slow. the

According to the current technology, the low-melting point polyester hot-melt adhesive decreases with the melting point, and its curing speed will also decrease, which leads to the problem of low efficiency during processing. Therefore, a fast-curing low-melting point polyester hot-melt adhesive is necessary. of. the

The present invention mainly accelerates the crystallization and solidification speed of the polymer through the long-chain aliphatic dibasic acid, so that it can have a low melting point and rapid crystallization ability at the same time. The polyester has a long straight-chain structure and good symmetry. The branched aliphatic dibasic acid, the branched structure of neopentyl glycol, and the heteroatoms contained in diethylene glycol reduce the regularity of the polymer structure, so that the crystallization time of the polyester can be adjusted according to the demand to meet the production requirements. the

Contents of the invention

The main purpose of the present invention is to provide a kind of preparation method of the polyester hot-melt adhesive of low melting point fast solidification in order to solve the above problems, compared with prior art, the polyester hot-melt adhesive prepared by this method has faster curing speed and lower melting point;

In order to achieve the above object, the steps of the present invention are as follows:

(1) Dodecanedioic acid and C ₂ -C ₄ dihydric alcohols are subjected to esterification reaction under the action of titanate catalysts and under the protection of inert gas. The reaction temperature is 160-230°C until the water produced by the reaction is distilled It ends when the output exceeds 93%;

(2) Add isophthalic acid, aliphatic dibasic acid, other dibasic alcohols and glycerol to the product of step (1) for esterification reaction at a reaction temperature of 210-230°C;

(3) Add a phosphorous acid stabilizer to the product of step (2), and co-condense under reduced pressure at 250-270°C and 100-150Pa, and the polycondensation time is 1-2 hours. The system is under normal pressure to obtain a molten copolymer, and the low-melting point copolyester hot melt adhesive is obtained from the discharge;

Said C ₂ -C ₄ dihydric alcohol is selected from one of ethylene glycol and butanediol;

The other dibasic alcohols are selected from pentanediol, diethylene glycol;

Said aliphatic dibasic acid is selected from adipic acid, suberic acid and sebacic acid. the

The mol ratio between described each component is:

Dodecanoic acid: aliphatic dibasic acid=1:0～0.05;

Dodecanoic acid: Isophthalic acid=1:0～0.05

C ₂ -C ₄ diols: other diols = 1:0.05～0.1;

C ₂ -C ₄ dihydric alcohol: glycerol=1:0～0.0002;

Total acid: total alcohol=1:1.15～1.5. the

The catalyst is selected from one of tetraethyl titanate, tetraisopropyl titanate and tetra-n-butyl titanate, and the mass of the catalyst is 0.01%-0.1% of the total acid mass. the

The stabilizer is selected from one of trimethyl phosphate and triphenyl phosphite, and the dosage of the stabilizer is 0.01%-0.1% of the total acid mass. the

Compared with the prior art, the present invention has the following advantages: the melting point of the product is lower than 100°C. The curing time is less than 2 minutes, and it is not easy to bond with each other, so it is suitable as an omentum adhesive material. the

Performance test: the melting point and melt index of the product obtained in the examples of the present invention are measured by international standard ISO 11357-1-1997 and national standard GB/T 3682-2000 respectively. the

Detailed ways

The present invention is illustrated below in conjunction with specific examples. the

Example 1

Add 423.2g of dodecanoic acid, 176.6g of ethylene glycol, and 0.045g of tetra-n-butyl titanate into a 2.0L polymerization reactor, start heating, until the temperature reaches 128°C, the raw materials dissolve, and start stirring; heat up to 166°C for distillation Produce by-product water, continue to heat up to 210°C, and the water output reaches 93% of the theoretical value, add 12.12g of sebacic acid, 15.6g of neopentyl glycol, and 16.6g of isophthalic acid, continue to heat up to 230°C, and distill off some excess Alcohol and reacted oligomers, add 0.045g of triphenyl phosphite, carry out decompression compression polymerization after the reaction distillate decreases, react under 100Pa system pressure, further increase the reaction temperature to 260 ° C, and the reaction time is 1 hour. Release the vacuum system under the protection of nitrogen, and the discharged product is a low-melting point polyester hot melt adhesive. After drying, the melting point is 85-88°C, the melting index is 51g/10min, and the curing time is 110s. the

Example 2

Add 313.95g of dodecanoic acid, 145.8g of butanediol, and 0.335g of tetraisopropyl titanate into a 2.0L polymerization reactor, start heating, until the temperature reaches 98°C, the raw materials dissolve, and start stirring; heat up to 170°C for distillation Produce by-product water, continue to heat up to 210°C, and the water output reaches 95% of the theoretical value, add 8.76g of adipic acid, 10.1g of neopentyl glycol, 12.75g of isophthalic acid, and 11.0g of diethylene glycol, and continue to heat up to 230°C, distill off part of excess alcohol and reacted oligomers, add 0.055g of triphenyl phosphite, carry out reduced pressure polymerization reaction after the reaction distillate is reduced, react under 100Pa system pressure, and further increase the reaction temperature to 254 ℃, the reaction time is 2 hours, and the vacuum system is released under the protection of nitrogen. The melting point of the discharged product is 82.7 ℃, the melting index is 48.7g/10min, and the curing time is 100s. the

Example 3

Add 432.4g of dodecanoic acid, 167.4g of ethylene glycol, and 0.2g of tetra-n-butyl titanate into a 2.0L polymerization reactor, start heating, until the temperature reaches 128°C, the raw materials dissolve, and start stirring; heat up to 166°C for distillation Produce by-product water, continue to heat up to 210°C, and the water output reaches 93% of the theoretical value, add 31.8g of diethylene glycol, 9.96g of isophthalic acid, and 8.76g of adipic acid, continue to heat up to 235°C, and distill off part of the excess Alcohol and reacted oligomers, add 0.451g of trimethyl phosphite, carry out decompression compression polymerization after the reaction distillate decreases, react under 100Pa system pressure, further increase the reaction temperature to 270°C, and the reaction time is 1.5 hours, The vacuum system was released under the protection of nitrogen, and the output product was a low melting point polyester hot melt adhesive. After drying, the melting point was 85.8°C, the melting index was 74.6g/10min, and the curing time was 110s. the

Example 4

Add 414g of dodecanoic acid, 172.98g of ethylene glycol, and 0.18g of tetra-n-butyl titanate into a 2.0L polymerization reactor, start heating, until the temperature reaches 128°C, the raw materials dissolve, and start stirring; heat up to 166°C to distill By-product water, continue to heat up to 210°C, the water output reaches 93% of the theoretical value, add 0.02g of glycerol, 17.4g of suberic acid, 16.6g of isophthalic acid, 29.0g of neopentyl glycol, continue to heat up to 230°C , distill off part of excess alcohol and reacted oligomers, add 0.063 g of triphenyl phosphite, carry out reduced-pressure compression polymerization reaction after the reaction distillate decreases, react under 150 Pa system pressure, and further increase the reaction temperature to 260 ° C, The reaction time was 1.8 hours, and the vacuum system was released under the protection of nitrogen. The discharged product was a low-melting point polyester hot melt adhesive. The melting point was 92.7°C, the melt index was 43.2g/10min, and the curing time was 120s. the

Example 5

Add 423.2g of dodecanoic acid, 167.4g of ethylene glycol, and 0.26g of tetra-n-butyl titanate into a 2.0L polymerization reactor, start heating, until the temperature reaches 128°C, the raw materials dissolve, and start stirring; heat up to 166°C for distillation Produce by-product water, continue to heat up to 210°C, and the water output reaches 95% of the theoretical value, add 14.6g of adipic acid, 9.96g of isophthalic acid, 31.8g of diethylene glycol, and 0.01g of glycerol, and continue to heat up to 230°C ℃, distill off part of the excess alcohol and the reacted oligomers, add 0.049g of triphenyl phosphite, and carry out the reduced-pressure compression polymerization reaction after the reaction distillate decreases, react under the system pressure of 120Pa, and further increase the reaction temperature to 265°C , The reaction time is 2 hours, the vacuum system is released under the protection of nitrogen, and the output product is a low-melting point polyester hot melt adhesive. After testing, its melting point is 85.2°C, the melt index is 45.8g/10min, and the curing time is 100s. the

Example 6

Add 414g of dodecanoic acid, 167.4g of ethylene glycol, and 0.2g of tetrabutyl titanate into a 2.0L polymerization reactor, start heating, until the temperature reaches 128°C, the raw materials dissolve, and start stirring; heat up to 166°C to distill out Product water, continue to heat up to 210°C, the water yield reaches 95% of the theoretical value, add 20.2g of sebacic acid, 16.6g of isophthalic acid, 31.2g of neopentyl glycol, continue to heat up to 230°C, distill off part of the excess alcohol and For the reaction oligomer, add 0.086g of triphenyl phosphite, carry out the reduced pressure compression polymerization reaction after the reaction distillate decreases, react under the system pressure of 100Pa, further increase the reaction temperature to 260°C, and the reaction time is 2 hours. The vacuum system is released under protection, and the output product is a low-melting point polyester hot-melt adhesive. After testing, its melting point is 81.3°C, its melting index is 41.2g/10min, and its curing time is 100s. the

Claims (3)

1. the preparation method of a copolyester with low melting point hot melt adhesive, its feature comprises the steps:

(1) ten two diacid and C ₂-C ₄dibasic alcohol, under the titanate ester catalyst action, carries out esterification under protection of inert gas, and temperature of reaction is 160-230 ℃, and the water generated to reaction is distilled out 93% end when above;

(2) in step (1) product, add m-phthalic acid, aliphatic dibasic acid, other dibasic alcohol and glycerol to carry out esterification, temperature of reaction 210-230 ℃;

(3) add phosphorous acid class stablizer in step (2) product, at 250-270 ℃, the copolycondensation of reducing pressure under 100-150Pa, the polycondensation time is 1-2 hour, when polycondensation completes, passes into nitrogen and makes the system normal pressure, obtain the molten state multipolymer, discharging obtains the copolyester with low melting point hot melt adhesive;

Said C ₂-C ₄dibasic alcohol is selected from a kind of in ethylene glycol, butyleneglycol;

Described other dibasic alcohol are selected from pentanediol, Diethylene Glycol;

Select oneself a kind of in diacid, nonane diacid, sebacic acid of said aliphatic dibasic acid;

Mol ratio between described each component is:

12 diacid: aliphatic dibasic acid=1: 0～0.05;

12 diacid: m-phthalic acid=1: 0～0.05;

C ₂-C ₄dibasic alcohol: other dibasic alcohol=1:0.05～0.1;

C ₂-C ₄dibasic alcohol: glycerol=1: 0～0.0002;

Total acid: total alcohol=1: 1.15～1.5;

Wherein the consumption of aliphatic dibasic acid and m-phthalic acid is non-vanishing.

2. method according to claim 1, is characterized in that catalyzer is selected from a kind of in tetraethyl titanate, titanium isopropylate, tetra-n-butyl titanate, and catalyst quality is 0.01%～0.1% of total acid quality.

3. method according to claim 1, is characterized in that stablizer is triphenyl phosphite, the 0.01%-0.1% that stabilizing agent dosage is the total acid quality.