CN113801619A

CN113801619A - Isosorbide-containing bio-based reactive polyurethane hot melt adhesive and preparation method thereof

Info

Publication number: CN113801619A
Application number: CN202111156016.8A
Authority: CN
Inventors: 李帅; 曹阳; 林鸿腾; 刘涛
Original assignee: Weldtone Xiamen Technology Co Ltd
Current assignee: Weldtone Xiamen Technology Co Ltd
Priority date: 2021-09-29
Filing date: 2021-09-29
Publication date: 2021-12-17

Abstract

A bio-based reactive polyurethane hot melt adhesive containing isosorbide and a preparation method thereof comprise the following components in parts by weight: 40-70 parts of bio-based polyester polyol; 10-25 parts of polyether polyol; 9-20 parts of polyisocyanate; 0.1-2 parts of a first catalyst; 0-2 parts of a first antioxidant; 0-30 parts of thermoplastic resin; 0-5 parts of a silane coupling agent; 0-10 parts of an auxiliary agent; the bio-based polyester polyol is prepared by condensation polymerization of bio-based dibasic acid and bio-based dihydric alcohol under the action of a second catalyst, and has the hydroxyl functionality of 1.95-2.3 and the molecular weight of 2000-5000; the bio-based diol contains isosorbide and also contains one or more of ethylene glycol, propylene glycol and butanediol prepared by a biological method. The invention meets the concept of environmental protection, and has the advantages of high bonding strength, good toughness, long opening time and the like.

Description

Isosorbide-containing bio-based reactive polyurethane hot melt adhesive and preparation method thereof

Technical Field

The invention relates to the field of bio-based reactive polyurethane hot melt adhesives, in particular to a bio-based reactive polyurethane hot melt adhesive containing isosorbide and a preparation method thereof.

Background

The polyester polyol is used as a key raw material for preparing polyurethane, and the structure and the performance of the polyester polyol have very important influence on the adhesive property, the mechanical property and the like of the reactive polyurethane hot melt adhesive, but most of the polyester polyol is derived from limited fossil resources. For example, patent CN201310248659.4 discloses a reactive polyurethane hot melt adhesive prepared by using petroleum-based dibasic acid and dihydric alcohol to synthesize polyester polyol through condensation reaction, and then reacting the polyester polyol with polyether polyol and polyisocyanate, and used for assembly and bonding of one or more of plastic, metal and glass.

The production of environment-friendly chemical products by using biomass resources as raw materials is the necessary way for human beings to realize sustainable development, and the research of bio-based products has become the leading edge of the world science and technology field. In order to improve the environmental protection property of the hot melt adhesive product, the patent CN201910516904.2 adopts bio-based raw material 2, 5-furandicarboxylic acid to replace petroleum-based raw material terephthalic acid, and copolymerizes with general petroleum-based diol to prepare bio-based copolyester based on 2, 5-furandicarboxylic acid, and the bio-based copolyester is used as the hot melt adhesive, and has the characteristics of appropriate pressing temperature, good bonding effect, short opening time, water washing resistance and the like when being applied to fabric bonding. However, the bio-based copolyester is prepared by directly using a high molecular weight polyester material as a hot melt adhesive, and does not have the function of continuous reaction, curing and crosslinking after the application of the reactive hot melt adhesive, so that the bonding strength is limited.

Isosorbide is considered as an important bio-based raw material next to lactic acid, and is the only sugar alcohol monomer for industrial production at present. Meanwhile, the unique chemical structure of isosorbide enables the isosorbide to be a bio-based platform compound used for constructing various macromolecules with high glass transition temperature and special performance. Therefore, the synthesis of high-performance high-molecular polymers from low-cost isosorbide as a raw material has become a research hotspot in the field of bio-based high-molecular materials. For example, patent CN202010010517.4 discloses that isosorbide and a compound containing active hydrogen are used as a composite initiator to perform ring-opening addition polymerization with an epoxy compound in the presence of an amine or metal catalyst to obtain isosorbide-based polyether, and the isosorbide-based polyether is used as a raw material to react with polyisocyanate to prepare a polyurethane material, which is used as a foam material with excellent compressive strength and low-temperature dimensional stability. Patent CN201911290614.7 adopts higher alcohol-acid ratio, reaction temperature and vacuum degree, isosorbide copolyester has been synthesized, the polyester molecular weight that this kind of method synthesized is great, the terminal group density is low and can't control two terminal groups and be hydroxyl, so only be used for the usage of conventional hot melt adhesive under the ordinary condition, but can't use as the polyester polyol of reaction type polyurethane hot melt adhesive, in addition, the isosorbide that this patent method adopted accounts for the mole ratio of dihydric alcohol and reaches 59.5% -81.3%, the isosorbide of high proportion rigidity dicyclic structure can make the glass transition temperature of polyester extremely high, the material is very fragile, can't satisfy reaction type polyurethane hot melt adhesive user demand.

In conclusion, polyester polyol serving as a key chemical raw material for preparing the polyurethane hot melt adhesive has extremely important influence on the bonding performance, the mechanical property and the like of the PUR, but most of the polyester polyol is derived from limited fossil fuel resource petroleum, so that the green and environment-friendly development of the polyurethane hot melt adhesive is limited to a great extent. At present, relevant researches and reports on the synthesis of isosorbide-based polyester polyol and application thereof are rare, particularly, when the isosorbide-based polyester polyol is applied to polyurethane hot melt adhesives, the hot melt adhesives prepared by adopting biological base materials such as isosorbide and the like in the prior art directly use polyester as the hot melt adhesives, and have no reactivity, so that the bonding strength is reduced.

Therefore, how to provide the polyester polyol which contains the isosorbide, has proper molecular weight, two end groups which are hydroxyl groups and proper material toughness, and the isosorbide-containing reactive polyurethane hot melt adhesive which has high reactivity and bonding strength and meets the green environmental protection concept is the problem to be solved.

Disclosure of Invention

The invention aims to solve the problems, and provides an isosorbide-containing bio-based reactive polyurethane hot melt adhesive and a preparation method thereof, which meet the green environmental protection concept and have the advantages of high reactivity, high bonding strength, good toughness, long opening time and the like.

The purpose of the invention is realized as follows:

the invention relates to an isosorbide-containing bio-based reaction type polyurethane hot melt adhesive, which comprises the following components in parts by weight:

the bio-based polyester polyol is represented by the general formula (I):

in the general formula (I), x represents a positive integer of 2-10, y represents an integer of 0-4, m represents a positive integer of 5-30, and n represents a positive integer of 3-10;

the bio-based polyester polyol is prepared by condensation polymerization of bio-based dibasic acid and bio-based dihydric alcohol under the action of a second catalyst, and has the hydroxyl functionality of 1.95-2.3 and the molecular weight of 2000-5000; the bio-based diol contains isosorbide, the bio-based diol also contains one or more of ethylene glycol, propylene glycol and butanediol prepared by a biological method, and the molar ratio of the isosorbide in the bio-based diol is 1-30%.

The bio-based reactive polyurethane hot melt adhesive containing isosorbide is characterized in that the bio-based dibasic acid is one or more selected from succinic acid, adipic acid, suberic acid, sebacic acid and dodecanedioic acid prepared by a biological method.

The bio-based reactive polyurethane hot melt adhesive containing isosorbide is characterized in that the bio-based dihydric alcohol is one or more selected from ethylene glycol, propylene glycol and butanediol prepared by a biological method.

The isosorbide-containing bio-based reactive polyurethane hot melt adhesive is prepared by the following steps:

adding bio-based dibasic acid and bio-based dihydric alcohol into a reactor connected with a fractionating tower at a distillation head according to the molar ratio of 1 to (1.05-1.2), adding tetrabutyl titanate as a second catalyst, heating to 140 ℃ and 160 ℃ for reaction for 1-2 hours, heating to 170 ℃ and 180 ℃ for reaction for 0.5-1.5 hours, controlling the temperature at the top of the fractionating tower at 100 ℃ and 102 ℃, distilling at normal pressure to remove at least 95 percent of the mass of the generated by-product water, adding a second antioxidant which is 0.1-1 percent of the total mass of the bio-based dibasic acid and the bio-based dihydric alcohol, heating to 210 ℃ and 220 ℃ for reaction for 1-2 hours, starting to vacuumize after the acid value is reduced to 20mg KOH/g, gradually increasing the vacuum degree, removing water and the rest of the bio-based dihydric alcohol under reduced pressure, and leading the reaction to proceed towards the direction of generating the low acid value polyester polyol, sampling every 15 minutes to measure the acid value and the hydroxyl value, and when the acid value is less than 1.0mg KOH/g and the hydroxyl value is less than 32mg KOH/g, cooling and discharging.

The isosorbide-containing bio-based reactive polyurethane hot melt adhesive is prepared by the following steps of, the first antioxidant and the second antioxidant are respectively one or more selected from 2, 6-tert-butyl-4-methylphenol, 4 '-thiobis (6-tert-butyl-3-methylphenol), pentaerythrityl tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 2' -methylenebis (4-methyl-6-tert-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, n-octadecyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, triphenyl phosphite and trinonyl phenyl phosphite.

In the isosorbide-containing bio-based reactive polyurethane hot melt adhesive, the polyisocyanate is a compound with two or more isocyanate groups at the molecular chain terminal; preferably, the polyisocyanate is selected from one or more of 4, 4' -diphenylmethane diisocyanate, naphthalene diisocyanate, toluene diisocyanate, p-phenylene diisocyanate, isophorone diisocyanate, 1, 6-hexamethylene diisocyanate, 1, 12-dodecane diisocyanate, cyclohexane-1, 4-diisocyanate and dicyclohexylmethane diisocyanate; more preferably, the polyisocyanate is 4, 4' -diphenylmethane diisocyanate.

The isosorbide-containing bio-based reaction type polyurethane hot melt adhesive is characterized in that the polyether polyol is one or more selected from polyoxyethylene polyol, polyoxypropylene polyol, polytetrahydrofuran polyol, polybutadiene diol and castor oil polyol, and the number average molecular weight of the polyether polyol is 1000-3000; when the molecular weight of the polyether polyol is less than 1000, the flexibility of the hot melt adhesive is reduced; when the molecular weight of the polyether polyol is more than 3000, the reactivity and the compatibility of the hot melt adhesive system can be reduced, so that the bonding strength of the hot melt adhesive is reduced.

The isosorbide-containing bio-based reactive polyurethane hot melt adhesive comprises a first catalyst, a second catalyst and a third catalyst, wherein the first catalyst is one or more selected from 2, 2-dimorpholinyl diethyl ether, an organic bismuth catalyst, dibutyltin dilaurate and stannous octoate; preferably, the first catalyst is 2, 2-dimorpholinodiethylether.

The isosorbide-containing bio-based reactive polyurethane hot melt adhesive is characterized in that the thermoplastic resin is one or more selected from polyurethane elastomers, acrylic resins, rosin resins, terpene resins, phenolic resins, carbon penta petroleum resins, carbon nonapetroleum resins, EVA resins, coumarone resins, dicyclopentadiene resins and styrene series resins.

The isosorbide-containing bio-based reactive polyurethane hot melt adhesive is characterized in that the silane coupling agent is one or more selected from gamma-aminopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyltrimethoxysilane, aniline methyl triethoxysilane, gamma- (2, 3-epoxypropoxy) propyl trimethoxysilane, beta- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane and gamma-urea propyl triethoxysilane; preferably, the silane coupling agent is gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane.

The isosorbide-containing bio-based reactive polyurethane hot melt adhesive comprises one or more of a curing accelerator, a stabilizer, a diluent, a toughening agent, a flame retardant, a pigment and a filler.

The preparation method of the isosorbide-containing bio-based reactive polyurethane hot melt adhesive comprises the following steps:

the method comprises the following steps: preparing raw materials according to the following components in parts by weight:

step two: adding the polyether polyol prepared in the step one and a first antioxidant into a reaction kettle, heating to 60-80 ℃, and stirring and mixing uniformly;

step three: adding the prepared bio-based polyester polyol and thermoplastic resin in the step one into a reaction kettle, heating to 150 ℃ and 170 ℃, uniformly stirring and mixing, and dehydrating for 2-4 hours under the condition that the vacuum degree is lower than-0.09 MPa;

step four: adding the polyisocyanate prepared in the step one into a reaction kettle, keeping the temperature at 150-170 ℃, and stirring and reacting for 0.5-2 hours under the condition that the vacuum degree is lower than-0.09 MPa;

step five: and (3) cooling to 110-.

The invention has the following beneficial effects:

(1) the invention adopts bio-based isosorbide and dihydric alcohol to carry out polycondensation reaction with bio-based dibasic acid to prepare bio-based polyester polyol containing isosorbide, the used raw materials are all produced by a biological method, and compared with petroleum-based raw materials used in the prior art, the bio-based polyester polyol can better meet the requirements of environmental protection;

(2) in the prepared bio-based polyester polyol, the isosorbide with a rigid double-ring structure is matched with the aliphatic dibasic acid and the dihydric alcohol in a limited way in types and parts, so that the crystallinity and the flexibility of chain segments of the prepared polyester polyol can be effectively adjusted, and the polyester polyol has rich ester bonds and polar groups, so that the cohesive force of the reactive polyurethane hot melt adhesive can be improved, and the polyester polyol has relatively excellent bonding performance;

(3) compared with the prior art that isosorbide copolyester is directly used as the hot melt adhesive, better bonding performance can be obtained through further curing and crosslinking reaction after sizing.

Drawings

FIG. 1 is an IR spectrum of a bio-based polyester polyol A1 used in example 1;

FIG. 2 is a drawing of Bio-based polyester polyol A1 used in example 1¹H-NMR chart;

FIG. 3 is an IR spectrum of bio-based polyester polyol A3 used in example 3;

FIG. 4 is a drawing of Bio-based polyester polyol A3 used in example 3¹H-NMR chart;

fig. 5 is a synthetic scheme for making bio-based polyester polyols of the present invention.

Detailed Description

The present invention will be further described with reference to the following examples.

As shown in fig. 5, is a synthetic scheme for the preparation of bio-based polyester polyols of the present invention, with specific reference to examples 1-5:

example 1

The preparation method of the bio-based polyester polyol A1 is as follows:

100g succinic acid, 63.8g propylene glycol and 13.6g isosorbide are added into a reactor connected with a fractionating tower at the distillation head, adding 0.09g of tetrabutyl titanate as a second catalyst, heating to 140 ℃ and 160 ℃ for reaction for 1.5 hours, then heating to 170-180 ℃ for reaction for 1 hour, controlling the temperature at the top of the fractionating tower at 100-102 ℃, distilling at normal pressure to remove at least 95 percent of the mass of the generated by-product water, 0.18g of tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester was added as an antioxidant, then heating to 210 ℃ and 220 ℃ for reaction for 1.5 hours, starting to vacuumize after the acid value is reduced to 20mg KOH/g, and gradually increasing the vacuum degree, decompressing to remove water and residual propylene glycol and isosorbide, and then leading the reaction to proceed toward the direction of generating the polyester polyol with low acid value. Sampling every 15 minutes to measure the acid value and the hydroxyl value, and when the acid value is less than 1.0mg KOH/g and the hydroxyl value is less than 32mg KOH/g, cooling and discharging to obtain the bio-based polyester polyol A1. FIG. 1 is an IR spectrum of a bio-based polyester polyol A1 used in example 1; FIG. 2 is a 1H-NMR chart of bio-based polyester polyol A1 used in example 1.

Example 2

The preparation method of the bio-based polyester polyol A2 is as follows:

100g of adipic acid, 52g of propylene glycol and 11.1g of isosorbide are introduced into a reactor which is connected to a fractionating column at the distillation head, adding 0.09g of tetrabutyl titanate as a second catalyst, heating to 140 ℃ and 160 ℃ for reaction for 1.5 hours, then heating to 170-180 ℃ for reaction for 1 hour, controlling the temperature at the top of the fractionating tower at 100-102 ℃, distilling at normal pressure to remove at least 95 percent of the mass of the generated by-product water, 0.18g of tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester was added as an antioxidant, then heating to 210 ℃ and 220 ℃ for reaction for 1.5 hours, starting to vacuumize after the acid value is reduced to 20mg KOH/g, and gradually increasing the vacuum degree, decompressing to remove water and residual propylene glycol and isosorbide, and then leading the reaction to proceed toward the direction of generating the polyester polyol with low acid value. Sampling every 15 minutes to measure the acid value and the hydroxyl value, and when the acid value is less than 1.0mg KOH/g and the hydroxyl value is less than 32mg KOH/g, cooling and discharging to obtain the bio-based polyester polyol A2.

Example 3

The preparation method of the bio-based polyester polyol A3 is as follows:

100g of suberic acid, 43.9g of propylene glycol and 9.4g of isosorbide were charged into a reactor to which a fractionating column was connected at the distillation head, adding 0.09g of tetrabutyl titanate as a second catalyst, heating to 140 ℃ and 160 ℃ for reaction for 1.5 hours, then heating to 170-180 ℃ for reaction for 1 hour, controlling the temperature at the top of the fractionating tower at 100-102 ℃, distilling at normal pressure to remove at least 95 percent of the mass of the generated by-product water, 0.18g of tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester was added as an antioxidant, then heating to 210 ℃ and 220 ℃ for reaction for 1.5 hours, starting to vacuumize after the acid value is reduced to 20mg KOH/g, and gradually increasing the vacuum degree, decompressing to remove water and residual propylene glycol and isosorbide, and then leading the reaction to proceed toward the direction of generating the polyester polyol with low acid value. Sampling every 15 minutes to measure the acid value and the hydroxyl value, and when the acid value is less than 1.0mg KOH/g and the hydroxyl value is less than 32mg KOH/g, cooling and discharging to obtain the bio-based polyester polyol A3. FIG. 3 is an IR spectrum of a bio-based polyester polyol A3 used in example 3; FIG. 4 is a 1H-NMR chart of bio-based polyester polyol A3 used in example 3.

Example 4

The preparation method of the bio-based polyester polyol A4 is as follows:

100g of sebacic acid, 38.2g of propylene glycol and 8.1g of isosorbide are introduced into a reactor which is connected to a fractionating column at the distillation head, adding 0.09g of tetrabutyl titanate as a second catalyst, heating to 140 ℃ and 160 ℃ for reaction for 1.5 hours, then heating to 170-180 ℃ for reaction for 1 hour, controlling the temperature at the top of the fractionating tower at 100-102 ℃, distilling at normal pressure to remove at least 95 percent of the mass of the generated by-product water, 0.18g of tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester was added as an antioxidant, then heating to 210 ℃ and 220 ℃ for reaction for 1.5 hours, starting to vacuumize after the acid value is reduced to 20mg KOH/g, and gradually increasing the vacuum degree, decompressing to remove water and residual propylene glycol and isosorbide, and then leading the reaction to proceed toward the direction of generating the polyester polyol with low acid value. Sampling every 15 minutes to measure the acid value and the hydroxyl value, and when the acid value is less than 1.0mg KOH/g and the hydroxyl value is less than 32mg KOH/g, cooling and discharging to obtain the bio-based polyester polyol A4.

Example 5

The preparation method of the bio-based polyester polyol A5 is as follows:

100g dodecanedioic acid, 33.8g propylene glycol and 7.2g isosorbide are introduced into a reactor which is connected to a fractionating column at the distillation head, adding 0.09g of tetrabutyl titanate as a catalyst, heating to 140 ℃ and 160 ℃ for reaction for 1.5 hours, then heating to 170-180 ℃ for reaction for 1 hour, controlling the temperature at the top of the fractionating tower at 100-102 ℃, distilling at normal pressure to remove at least 95 percent of the mass of the generated by-product water, 0.18g of tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester was added as an antioxidant, then heating to 210 ℃ and 220 ℃ for reaction for 1.5 hours, starting to vacuumize after the acid value is reduced to 20mg KOH/g, and gradually increasing the vacuum degree, decompressing to remove water and residual propylene glycol and isosorbide, and then leading the reaction to proceed toward the direction of generating the polyester polyol with low acid value. Sampling every 15 minutes to measure the acid value and the hydroxyl value, and when the acid value is less than 1.0mg KOH/g and the hydroxyl value is less than 32mg KOH/g, cooling and discharging to obtain the bio-based polyester polyol A5.

The bio-based polyester polyols were prepared by the above examples 1-5 to obtain bio-based polyester polyol a1, bio-based polyester polyol a2, bio-based polyester polyol A3, bio-based polyester polyol a4 and bio-based polyester polyol a5, respectively; the number average molecular weight of the biobased polyester polyol A1 is 3544 measured by a gel chromatograph, the hydroxyl value of the biobased polyester polyol A1 is 31.2 measured by a titration method, and the acid value is 0.41 measured by a titration method; the number average molecular weight of the bio-based polyester polyol A2 is 3566 measured by a gel chromatograph, and the hydroxyl value of the bio-based polyester polyol A2 is 30.9 and the acid value is 0.53 measured by a titration method; the number average molecular weight of the biobased polyester polyol A3 is 3517 measured by a gel chromatograph, and the hydroxyl value of the biobased polyester polyol A3 is 31.1 and the acid value is 0.82 measured by a titration method; the number average molecular weight of the biobased polyester polyol A4 is 3539 measured by a gel chromatograph, the hydroxyl value of the biobased polyester polyol A4 is 31.1 measured by a titration method, and the acid value is 0.62 measured by a titration method; the number average molecular weight of the bio-based polyester polyol A5 was 3523 as measured by gel chromatography, and the hydroxyl value and acid value of the bio-based polyester polyol A5 were 31.4 and 0.45 as measured by titration.

Example 6

A preparation method of isosorbide-containing bio-based reactive polyurethane hot melt adhesive comprises the following steps:

s1: preparing raw materials according to the following components in parts by weight:

s2: adding the polyether polyol prepared in the S1 and a first antioxidant into a reaction kettle, heating to 70 ℃, and stirring and mixing uniformly;

s3: adding the prepared bio-based polyester polyol A1 in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition that the vacuum degree is lower than-0.09 MPa;

s4: adding the polyisocyanate prepared in S1 into the reaction kettle, keeping the temperature at 160 ℃, and stirring and reacting for 1 hour under the condition that the pressure is lower than-0.09 MPa;

s5: and (3) cooling to 120 ℃, adding the first catalyst prepared in the S1 into the reaction kettle, stirring and mixing for 0.5 hour, then carrying out vacuum defoamation for 30 minutes, rapidly discharging under the protection of nitrogen, and packaging in an aluminum foil bag or a rubber barrel.

Example 7

s3: adding the prepared bio-based polyester polyol A2 in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition that the vacuum degree is lower than-0.09 MPa;

s4: adding the polyisocyanate prepared in the S1 into a reaction kettle, keeping the temperature at 160 ℃, and stirring and reacting for 1 hour under the condition of being lower than-0.09 MPa;

Example 8

s3: adding the prepared bio-based polyester polyol A3 in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Example 9

s3: adding the prepared bio-based polyester polyol A4 in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Example 10

s3: adding the prepared bio-based polyester polyol A5 in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Example 11

s3: adding the prepared bio-based polyester polyol A1 and the thermoplastic resin in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

s5: cooling to 120 ℃, adding the first catalyst, the silane coupling agent and the auxiliary agent prepared in the step S1 into a reaction kettle, stirring and mixing for 0.5 hour, and then carrying out vacuum defoaming for 30 minutes; and (4) rapidly discharging under the protection of nitrogen and packaging in an aluminum foil bag or a glue barrel.

Example 12

s3: adding the prepared bio-based polyester polyol A2 and the thermoplastic resin in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Example 13

s3: adding the prepared bio-based polyester polyol A3 and the thermoplastic resin in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Example 14

s3: adding the prepared bio-based polyester polyol A4 and the thermoplastic resin in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Example 15

s3: adding the prepared bio-based polyester polyol A5 and the thermoplastic resin in the S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Example 16

Example 17

Example 18

Example 19

Example 20

Example 21

Example 22

Example 23

Example 24

Example 25

Example 26

Example 27

Example 28

Example 29

Example 30

Comparative example 1

A preparation method of a reactive polyurethane hot melt adhesive comprises the following steps:

s3: adding the polyester polyol Dynacoll 7360 prepared in S1 into a reaction kettle, heating to 160 ℃, stirring and mixing uniformly, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Comparative example 2

s3: adding polyester polyol Dynacoll 7360 prepared in S1 and thermoplastic resin into a reaction kettle, heating to 160 ℃, stirring and mixing uniformly, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

Comparative example 3

The preparation method of the isosorbide copolyester comprises the following steps:

adding dihydric alcohol consisting of 210.44g of isosorbide, 35.45g of hexanediol and 24g of polyethylene glycol (Mn is 400), dibasic acid consisting of 99.68g of terephthalic acid, 135.58g of dimer acid and 72.81g of sebacic acid, and 0.15g of tetrabutyl titanate serving as a catalyst into a 1L reaction kettle for esterification, wherein the initial reaction temperature is 165 ℃, the temperature is gradually increased to 225 ℃, and when the water amount generated by the reaction reaches more than 95% of the theoretical water yield, the esterification is finished; the reaction temperature is controlled to be 235-250 ℃, the polycondensation reaction is carried out under the vacuum condition of 90-180 Pa, the reaction is finished after 2h, and 0.09g of antioxidant tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester is added ten minutes before the reaction is finished.

Comparative example 4

s3: adding the prepared isosorbide copolyester of S1 into a reaction kettle, heating to 160 ℃, uniformly stirring and mixing, and dehydrating for 3 hours under the condition of being lower than-0.09 MPa;

s5: cooling to 120 ℃, adding the first catalyst prepared in the step S1 into a reaction kettle, stirring and mixing for 0.5 hour, then carrying out vacuum defoamation for 30 minutes, rapidly discharging under the protection of nitrogen, and packaging in an aluminum foil bag or a rubber barrel;

wherein the isosorbide copolyester is prepared by the preparation method of comparative example 3.

Examples 6-15 and comparative examples 1-4, the polyether polyol was a polypropylene oxide PPG2000 selected from Voranol 2000LM of Dow, USA; the polyisocyanate is 4, 4' -diphenylmethane diisocyanate selected from MDI-100 from Vanhua chemical company; the first catalyst is 2, 2-dimorpholinodiethylether (DMDEE) CAS number 6425-39-4; the first antioxidant is pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] selected from Irganox 1010 from BASF, Germany; the silane coupling agent is gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane selected from KBM-403 of Japan shin-Etsu corporation; the tackifying resin is acrylate resin selected from BR106 of Mitsubishi corporation; the polyester polyol in comparative examples 1-2 was selected from Dynacoll 7360, a winning company.

The samples obtained in examples 6 to 15 and comparative examples 1 to 4 were subjected to the following performance tests, respectively, and the test results are shown in the following table 1:

1. opening time: the hot melt adhesives obtained in the examples and comparative examples were applied to a polycarbonate substrate at a width of 2mm using a dispenser, immediately after dispensing was completed, a stopwatch was used to start timing, the adhesive line was lightly touched with a finger, when the touch adhesive line did not stick to the hand, timing was completed, and the time was recorded as the open time of the hot melt adhesive in seconds(s).

2. Bonding strength: the adhesive property (tensile shear strength) of the hot melt adhesive is tested according to the determination of the tensile shear strength of the adhesive (rigid material to rigid material) in standard GB/T7124-. Selecting a polycarbonate substrate, wherein the size of the substrate is 100mm multiplied by 25mm multiplied by 2mm, lapping the two substrates together, the bonding area is 12.5mm multiplied by 25mm, the thickness of a glue layer is ensured to be 0.2mm, placing a lapped sample strip in a constant temperature and humidity box with the temperature of 25 ℃ and the humidity of 50% RH for curing for seven days, and testing the tensile shear strength by adopting a universal material tensile testing machine, wherein the tensile speed is 5 mm/min;

3. elongation at break: tensile elongation at Break determination of tensile Properties of plastics part 3 according to the Standard GB/T1040.3-2006: experimental conditions for films and sheets. Firstly, injecting a hot melt adhesive into a tetrafluoroethylene mold with the thickness of 2mm, strickling, and putting the tetrafluoroethylene mold into a constant temperature and humidity box with the temperature of 25 ℃ and the humidity of 50% RH for moisture curing for 7 days; cutting the cured hot melt adhesive film by using a dumbbell-shaped cutter with the size of 6mm multiplied by 115mm to prepare a sample strip, and performing a tensile property test on the sample strip at room temperature by using a WDW3020 type electronic universal tester with the tensile speed of 10 mm/min;

4. content of bio-based: the weight percentage of the bio-based raw materials adopted in the prepared reactive polyurethane hot melt adhesive in the total mass of the hot melt adhesive product is calculated.

TABLE 1 results of Performance test of examples 6 to 15 and comparative examples 1 to 4

Comparative examples 1 to 30 and comparative examples 1 to 4 were analyzed in conjunction with table 1, and the isosorbide-containing bio-based reactive polyurethane hot melt adhesive of the present invention was able to obtain an environmentally friendly reactive polyurethane hot melt adhesive by using the prepared bio-based polyester polyol as a raw material, while by comparing examples 6 to 10 with comparative example 1, and comparing examples 11 to 15 with comparative example 2, it was found that the adhesive property and elongation at break of the isosorbide-containing bio-based reactive polyurethane hot melt adhesive were significantly superior to those of the reactive polyurethane hot melt adhesive using the polyester polyol prepared from the conventional petroleum-based raw material as a component under the same composition data; through comparison of examples 16-30 with comparative example 2, it can also be seen that within the weight parts of the composition of the present invention, the adhesive properties and elongation at break of the isosorbide-containing bio-based reactive polyurethane hot melt adhesive are significantly better than those of a reactive polyurethane hot melt adhesive using a polyester polyol prepared from a conventional petroleum-based raw material as a component; through the analysis and comparison of the examples 6-15 and the comparative examples 3-4, it can be found that the isosorbide copolyester obtained by simply carrying out esterification and polycondensation on the bio-based diol and the bio-based diacid can be directly used as the hot melt adhesive, the bonding strength and the elongation at break can not be ensured, the isosorbide copolyester is used as a component of the reaction type polyurethane hot melt adhesive, the obtained reaction type polyurethane hot melt adhesive still can not obtain better bonding strength and elongation at break, the toughness of the comparative examples 3-4 is extremely poor, and meanwhile, the bio-based content of the comparative examples 3-4 is also obviously lower than that of the examples 6-15, so that the technical scheme for synthesizing the bio-based polyester polyol in the patent of the invention has a good effect of improving the performance of the reaction type polyurethane hot melt adhesive; in addition, through comparison of examples 6-10 with comparative example 1 and comparison of examples 11-30 with comparative example 2, it can be seen that the isosorbide-containing bio-based reactive polyurethane hot melt adhesive of the present invention has extremely excellent open time, the open time of comparative examples 3-4 is also significantly lower than that of examples 6-30, and the long open time provides a more flexible sizing operation mode for the polyurethane hot melt adhesive, and is particularly suitable for some special occasions with extremely high requirements on operation time. Therefore, the bio-based reactive polyurethane hot melt adhesive disclosed by the invention uses self-made bio-based polyester polyol as a raw material, and the bio-based polyester polyol has a structure that two end groups are hydroxyl groups through the preparation method, the components and the weight parts of the components, and has the advantages of proper molecular weight and good toughness; on the basis of further improving the environmental protection performance, the bio-based reactive polyurethane hot melt adhesive can reach and exceed the bonding performance of the traditional hot melt adhesive, has extremely long open time, and ensures excellent performance and extremely wide application occasions while really solving the environmental protection problem of the reactive polyurethane hot melt adhesive.

The above embodiments are provided only for illustrating the present invention and not for limiting the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and therefore all equivalent technical solutions should also fall within the scope of the present invention, and should be defined by the claims.

Claims

1. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive is characterized by comprising the following components in parts by weight:

the bio-based polyester polyol is represented by the general formula (I):

the bio-based polyester polyol is prepared by condensation polymerization of bio-based dibasic acid and bio-based dihydric alcohol under the action of a second catalyst, and has the hydroxyl functionality of 1.95-2.3 and the molecular weight of 2000-; the bio-based diol contains isosorbide, the bio-based diol also contains one or more of ethylene glycol, propylene glycol and butanediol prepared by a biological method, and the molar ratio of the isosorbide in the bio-based diol is 1% -30%.

2. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 1, wherein the bio-based diacid is selected from one or more of succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid prepared by a biological process.

3. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 1, wherein the bio-based polyester polyol is prepared by:

adding the bio-based dibasic acid and the bio-based dihydric alcohol into a reactor connected with a fractionating tower at a distillation head according to the molar ratio of 1 to (1.05-1.2), adding tetrabutyl titanate as a second catalyst, heating to 140-, sampling every 15 minutes to measure the acid value and the hydroxyl value, and when the acid value is less than 1.0mg KOH/g and the hydroxyl value is less than 32mg KOH/g, cooling and discharging.

4. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 3, the first antioxidant and the second antioxidant are respectively selected from one or more of 2, 6-tert-butyl-4-methylphenol, 4 '-thiobis (6-tert-butyl-3-methylphenol), pentaerythrityl tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 2' -methylenebis (4-methyl-6-tert-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, n-octadecyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, triphenyl phosphite and trinonyl phenyl phosphite.

5. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 1, wherein the first catalyst is selected from the group consisting of 2, 2-dimorpholinodiethyl ether, organobismuth catalysts, dibutyltin dilaurate and stannous octoate.

6. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 1, wherein the polyisocyanate is a compound having two or more isocyanate groups at the molecular chain terminals.

7. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 1, wherein the polyether polyol is selected from one or more of polyoxyethylene polyol, polyoxypropylene polyol, polytetrahydrofuran polyol, polybutadiene diol, castor oil polyol and copolymer polyols of two or more thereof, and the number average molecular weight of the polyether polyol is 1000-3000.

8. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 1, wherein the thermoplastic resin is selected from one or more of polyurethane elastomers, acrylic resins, rosin resins, terpene resins, phenolic resins, carbo penta petroleum resins, carbo nona petroleum resins, EVA resins, coumarone resins, dicyclopentadiene resins, and styrenic resins.

9. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 1, wherein the silane coupling agent is selected from one or more of gamma-aminopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyltrimethoxysilane, anilinomethyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane, beta- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, and gamma-ureidopropyltriethoxysilane.

10. The isosorbide-containing bio-based reactive polyurethane hot melt adhesive of claim 1, wherein the adjuvant is one or more of a curing accelerator, a stabilizer, a diluent, a toughening agent, a flame retardant, a pigment and a filler.

11. The preparation method of the isosorbide-containing bio-based reactive polyurethane hot melt adhesive, according to claim 1, is characterized in that the preparation method of the isosorbide-containing bio-based reactive polyurethane hot melt adhesive comprises the following steps:

step two: adding the polyether polyol prepared in the first step and a first antioxidant into a reaction kettle, heating to 60-80 ℃, and stirring and mixing uniformly;

step three: adding the prepared bio-based polyester polyol and thermoplastic resin in the step one into the reaction kettle, heating to 150 ℃ and 170 ℃, uniformly stirring and mixing, and dehydrating for 2-4 hours under the condition that the vacuum degree is lower than-0.09 MPa;

step four: adding the polyisocyanate prepared in the step one into the reaction kettle, keeping the temperature at 150-170 ℃, and stirring and reacting for 0.5-2 hours under the condition that the vacuum degree is lower than-0.09 MPa;

step five: and (3) cooling to 110-.