CN115960560A - Moisture reactive rubber hot melt adhesive and preparation method thereof - Google Patents

Abstract

A moisture reactive rubber hot melt adhesive and a preparation method thereof are disclosed, wherein the moisture reactive rubber hot melt adhesive comprises the following components in parts by weight: 20-40 parts of SBC rubber polymer; 5-10 parts of diene liquid rubber with at least one terminal group having an active hydrogen functional group; 35-45 parts of synthetic resin; 0-20 parts of tackifying resin; 0-35 parts of a plasticizer; 0-1 part of antioxidant; 5-20 parts of isocyanate. The invention effectively realizes the reaction of the active hydrogen compound and isocyanate by utilizing the diene liquid rubber with at least one end group having the active hydrogen functional group, so that the active hydrogen compound is matched with the polarity of the SBC rubber polymer, the stability of the system is effectively ensured, and the initial strength, the final strength and the strength under the high-temperature and high-humidity conditions are balanced, so that the product obtained by the patent has wide application range and good stability.

Description

Moisture reactive rubber hot melt adhesive and preparation method thereof

Technical Field

The invention relates to the field of adhesives, in particular to a moisture reactive rubber hot melt adhesive and a preparation method thereof.

Background

The traditional SBR rubber type hot melt adhesive is prepared by simply and physically mixing SBR elastomer, petroleum resin, tackifying resin and plasticizer, can obtain the hot melt adhesive with certain initial strength by formula adjustment, and is widely applied to the label, adhesive tape, packaging industries and the like. But because no chemical crosslinking exists in the system, the system has poor performance under severe weather conditions such as high temperature resistance, high humidity resistance and the like;

although the technology of obtaining polymers with groups such as carbamate and carbamido by using active hydrogen and isocyanate is relatively extensive, adhesives based on the polymers cannot achieve higher initial strength;

meanwhile, a polymer obtained by reacting a general active hydrogen compound with isocyanate has higher polarity, has larger polarity difference with SBC, cannot obtain a stable system, and cannot directly use a moisture curing system in the SBR rubber hot melt adhesive at present. Therefore, researchers are always puzzled on how to enable the SBR hot melt adhesive to have excellent performances of high temperature, high humidity and other severe weather conditions on the basis of ensuring the initial strength.

Disclosure of Invention

The first purpose of the invention is to provide a moisture reaction type rubber hot melt adhesive which has stable integral system and balanced performance, and achieves balance in the aspects of initial strength, final strength and strength under high-temperature and high-humidity conditions;

the second purpose of the invention is to provide a preparation method of the moisture reaction type rubber hot melt adhesive.

In order to achieve the purpose, the specific method is that the moisture reactive rubber hot melt adhesive comprises the following components in parts by weight:

further, the SBC rubber polymer is one or more of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-isoprene/butadiene, styrene-ethylene/butylene-styrene, styrene-ethylene/propylene-styrene, styrene-ethylene/butylene/styrene-styrene, maleic anhydride-modified styrene-ethylene/butylene-styrene, and vinyl-terminated styrene-butadiene-styrene.

Further, the diene liquid rubber with at least one terminal group having an active hydrogen functional group is one or more of polybutadiene and polyisoprene rubber.

Further, the diene liquid rubber with at least one end group having an active hydrogen functional group is a diene liquid rubber with at least one end group containing one or more of amino, hydroxyl or carboxyl functional groups.

Further, the synthetic resin is one or more of an unhydrogenated aliphatic petroleum resin, an unhydrogenated aromatic petroleum resin, an unhydrogenated aliphatic/aromatic copolymer resin, an unhydrogenated styrene resin, a hydrogenated aliphatic petroleum resin, a hydrogenated aromatic petroleum resin, a hydrogenated aliphatic/aromatic copolymer resin, and a hydrogenated styrene resin.

Further, the tackifying resin is one or more of rosin, rosin derivatives, terpene resins and terpene resin derivatives.

Further, the plasticizer is naphthenic oil.

Further, the antioxidant is at least one selected from pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], tris [2, 4-di-tert-butylphenyl ] phosphite and n-octadecyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

Further, the isocyanate is one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate trimer, dicyclohexylmethane diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, L-lysine triisocyanate and polymethylene polyphenyl polyisocyanate.

Further, the preparation method of the moisture reactive rubber hot melt adhesive comprises the following steps:

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

s2: adding the SBC rubber polymer prepared in the S1, a plasticizer and an antioxidant into a reactor, heating to 140-170 ℃, continuously stirring until all materials in the reactor are molten, and then reacting and stabilizing for 15min;

s3: adding the diene liquid rubber, the tackifying resin and the synthetic resin which are prepared in the step S1 and at least one end group of which has an active hydrogen functional group into the reactor while stirring at the temperature of 140-170 ℃, vacuumizing and stirring for 120min, adding the isocyanate prepared in the step S1 at the temperature of 140-170 ℃, reacting for 60min, and then performing defoaming treatment.

The system disclosed by the invention has good stability, better viscosity, final strength, duPont falling ball impact resistance and high temperature and high humidity resistance are ensured under the condition of simultaneously improving the initial strength, the whole system is stable, the performances in all aspects are balanced, and the product obtained by the patent is wide in application range and good in stability.

Detailed Description

Example 1

Adding 20 parts of styrene-isoprene-styrene, 15 parts of naphthenic oil and 0.2 part of tris [2, 4-di-tert-butylphenyl ] phosphite into a reactor, heating to 150 ℃, stirring until all materials are molten, and stabilizing the reaction for 15min; then, under the condition of stirring, 10 parts of carboxyl-terminated polybutadiene liquid rubber, 10 parts of rosin and 45 parts of styrene resin are added, the vacuum pumping and stirring are carried out for 120min, then 10 parts of diphenylmethane diisocyanate are added, the reaction is carried out for 60min at the temperature of 150 ℃, finally, the defoaming is carried out, the mixture is filled into an opaque rubber tube, and the sealing and the storage are carried out.

Example 2

Adding 20 parts of styrene-isoprene-styrene, 15 parts of naphthenic oil and 0.2 part of tris [2, 4-di-tert-butylphenyl ] phosphite into a reactor, heating to 150 ℃, stirring until all materials are molten, and stabilizing the reaction for 15min; then, under the condition of stirring, 10 parts of hydroxyl-terminated polybutadiene liquid rubber, 10 parts of rosin and 45 parts of styrene resin are added, the vacuum pumping and stirring are carried out for 120min, then 10 parts of diphenylmethane diisocyanate are added, the reaction is carried out for 60min at the temperature of 150 ℃, finally, the defoamed mixture is filled into an opaque rubber tube, and the sealed storage is carried out.

Example 3

Adding 20 parts of styrene-isoprene-styrene, 15 parts of naphthenic oil and 0.2 part of tris [2, 4-di-tert-butylphenyl ] phosphite into a reactor, heating to 150 ℃, stirring until all materials are molten, and stabilizing the reaction for 15min; then, under the condition of stirring, 10 parts of amino-terminated polybutadiene liquid rubber, 10 parts of rosin and 45 parts of styrene resin are added, the mixture is vacuumized and stirred for 120min, 10 parts of diphenylmethane diisocyanate is added, the mixture reacts for 60min at the temperature of 150 ℃, and finally, the mixture is defoamed, filled into an opaque rubber tube and sealed and stored.

Example 4

Adding 30 parts of styrene-isoprene-styrene, 20 parts of naphthenic oil and 0.5 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester into a reactor, heating to 150 ℃, stirring until all materials are molten, and reacting stably for 15min; then, under the stirring condition, 5 parts of amino-terminated polybutadiene liquid rubber, 10 parts of terpene resin and 35 parts of styrene resin are added, the vacuum pumping and the stirring are carried out for 120min, then 10 parts of diphenylmethane diisocyanate are added, the reaction is carried out for 60min at the temperature of 150 ℃, finally, the defoaming is carried out, the mixture is filled into an opaque rubber tube, and the sealed preservation is carried out.

Example 5

Adding 30 parts of maleic anhydride-modified styrene-butylene-styrene, 35 parts of naphthenic oil and 1 part of tris [2, 4-di-tert-butylphenyl ] phosphite into a reactor, heating to 150 ℃, stirring until all materials are molten, and stabilizing the reaction for 15min; then, under the stirring condition, 5 parts of amino-terminated polybutadiene liquid rubber and 35 parts of carbon penta-petroleum resin are added, the vacuum pumping and the stirring are carried out for 120min, then 10 parts of diphenylmethane diisocyanate are added, the reaction is carried out for 60min at the temperature of 150 ℃, finally, the defoaming is carried out, the mixture is filled into an opaque rubber tube, and the sealing and the preservation are carried out.

Example 6

Adding 40 parts of styrene-ethylene-styrene and 1 part of tris [2, 4-di-tert-butylphenyl ] phosphite into a reactor, heating to 150 ℃, stirring until all materials are molten, and stabilizing the reaction for 15min; then, under the condition of stirring, 10 parts of hydroxyl-terminated polybutadiene liquid rubber, 45 parts of carbon-nine petroleum resin and 20 parts of terpene resin are added, the vacuum pumping and the stirring are carried out for 120min, then 10 parts of diphenylmethane diisocyanate are added, the reaction is carried out for 60min at the temperature of 150 ℃, finally, the defoamed materials are filled into an opaque rubber tube, and the sealed storage is carried out.

Example 7

Adding 40 parts of styrene-ethylene-styrene, 15 parts of naphthenic oil and 1 part of beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) n-octadecyl propionate into a reactor, heating to 150 ℃, stirring until all materials are molten, and reacting stably for 15min; then, under the stirring condition, 5 parts of hydroxyl-terminated isoprene liquid rubber, 35 parts of carbon nonapetroleum resin and 5 parts of terpene resin are added, the vacuum pumping and the stirring are carried out for 120min, then 10 parts of diphenylmethane diisocyanate are added, the reaction is carried out for 60min at the temperature of 150 ℃, finally, the defoamation is carried out, the opaque rubber tube is filled, and the sealing and the preservation are carried out.

Comparative example 1 (conventional PUR moisture curing adhesive System)

Adding 20 parts of poly (hexanediol adipate-diol), 15 parts of poly (hexanediol sebacate) diol, 15 parts of amorphous polyester diol, 15 parts of polypropylene diol, 5 parts of thermoplastic polyurethane tackifying resin, 20 parts of methyl methacrylate and acrylate copolymer, and 0.2 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester into a reactor, heating to 140 ℃, stirring until the materials are completely molten, and stabilizing the reaction for 120min; and then adding 10 parts of diphenylmethane diisocyanate under the stirring condition, stirring for 60min, defoaming, filling into a rubber tube, sealing and storing, thus obtaining the existing reactive polyurethane hot melt adhesive.

Comparative example 2 (traditional SBR rubber type hot melt system)

Adding 20 parts of styrene-ethylene-styrene, 15 parts of naphthenic oil and 0.2 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester into a reactor, heating to 150 ℃, stirring until all materials are molten, and stabilizing the reaction for 15min; and then, under the stirring condition, adding 20 parts of rosin and 45 parts of carbon five petroleum resin, stirring for 30min, finally defoaming, filling into an opaque rubber tube, sealing and storing, wherein the existing traditional SBC rubber type hot melt adhesive is obtained.

Comparative example 3 (conventional SBR Hot melt adhesive directly mixed with moisture reactive polyurethane Polymer)

Adding 20 parts of styrene-ethylene-styrene, 15 parts of naphthenic oil and 0.2 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester into a reactor, heating to 150 ℃, stirring until all materials are molten, and reacting for 15min; then under the stirring condition, 10 parts of polypropylene glycol (Mn = 2000), 10 parts of rosin and 45 parts of carbon pentapetroleum resin are added, the vacuum pumping and the stirring are carried out for 120min, then 10 parts of diphenylmethane diisocyanate are added, the reaction is carried out for 60min at the temperature of 150 ℃, finally, the defoaming is carried out, the mixture is filled into an opaque rubber tube, and the sealing and the storage are carried out, so that the moisture reaction type SBC hot melt adhesive obtained by the conventional polyurethane route is obtained.

Examples 1-7 and comparative examples 1-3 were tested as follows:

1. the viscosity test adopts a Brookfield rotational viscometer, the tested sample is preheated for 10min at 170 ℃, the completely preheated sample is poured into a sample cup, the sample cup is fixed in a heater, the position is adjusted to ensure that a rotor on the viscometer is positioned at the center of the tested sample of the sample cup, the temperature of the heater is adjusted, the rotor and the tested sample are kept constant temperature for 10min in the sample cup, the temperature of the sample is ensured to be stable at 170 ℃, and the temperature of the sample is within +/-1 ℃ of the specified temperature; keeping the temperature at 170 ℃, opening a rotor, continuously rotating for 20min, and reading the viscosity data at the moment, wherein the viscosity unit is 'cps';

2. and (3) testing the thrust strength:

1) Test initial thrust strength/Mpa (5 min thrust strength): dispensing a tested sample adhesive on the surface of a base material by a table type dispenser, gluing two pieces of base materials according to the surface of the base material by using a base material die, controlling the thickness of the adhesive to be 0.15mm, the weight of the adhesive to be 0.05 +/-0.003 g, maintaining the pressure by using 2kg of force, placing the base materials in an environment with the temperature of 23 +/-2 ℃ and the relative humidity of 50 +/-5 ℃ for 5min for initial time, and testing by using a three-throw universal testing machine until the time is up, so that a clamp holder of the testing machine loads a sample at the moving speed of 10mm/min and records the maximum load and the bonding area of the sample damaged by pushing force;

2) Test of final thrust strength Mpa (thrust 48 hours final strength): the method comprises the following steps of dispensing a tested sample adhesive on the surface of a base material through a table type dispenser, bonding two base materials together by using a base material die, controlling the thickness of the adhesive to be 0.15mm and the weight of the adhesive to be 0.05 +/-0.003 g, keeping the pressure by using 2kg of force, placing the base material die in an environment with the temperature of 23 +/-2 ℃ and the relative humidity of 50 +/-5 ℃ for 48 hours, finally curing the base material, testing by using a three-throw universal testing machine when the time is up, loading a sample by using a clamp holder of the testing machine at the moving speed of 10mm/min, and recording the maximum load and the bonding area of the sample damaged by pushing force.

The sample preparation is carried out by a table-type dispensing machine, and a glue line track is drawn on the surface of the base material through the movement of three axes of X, Y and Z in the moving direction;

3. dupont ball impact test after 48 hours: dispensing a tested sample adhesive on the surface of a base material by a table type dispenser, bonding two base materials together by using a base material mould, controlling the thickness of the adhesive to be 0.15mm and the weight of the adhesive to be 0.05 +/-0.003 g, keeping the pressure by using 2kg of force, placing the base materials in an environment with the temperature of 23 +/-2 ℃ and the relative humidity of 50 +/-5 ℃ for 48h for final curing, placing the cured base materials in a DuPont falling ball impact tester, and recording the impact times of the tested sample when the base materials are peeled off under the conditions of 200g and 70 mm.

4. And (3) high-temperature high-humidity aging test, namely curing the tested sample for 48h (the curing process is the same as that of the DuPont falling ball impact test at the point 3), aging the sample in an Aisback constant-temperature constant-humidity box, aging the sample in the Aisback constant-temperature constant-humidity box for 72h, taking out the tested sample, and testing the aged strength of the sample by adopting a normal-temperature thrust method. The test selects two environmental conditions for aging, wherein one environmental condition is that the temperature is 85 ℃ and the humidity is 85 percent; another ambient condition is a temperature of 60 ℃ and a humidity of 90%. The experimental data for the above tests are reported in table 1:

TABLE 1 comparative and example test data Table

As can be seen from the test data in table 1 above: comparative example 1 is that the initial thrust strength/Mpa (5 min thrust strength) of the conventional PUR moisture curing adhesive system is very low, the data obtained by the three substrates is between 0.08 and 0.11, the difference between 0.68 and 1.41 is very large compared with examples 1 to 7, the low initial strength is difficult to meet the situation that the adhesive needs to provide high strength in a short time, the low initial strength polyurethane hot melt adhesive needs to be released after applying certain pressure for several hours to meet the requirement in common use, so a pressure maintaining jig needs to be additionally used, the industrial cost is wasted, and the improvement of the initial strength is particularly important.

Comparative example 2 is a conventional SBR rubber type hot melt adhesive system which is prepared by simply physically mixing an SBR elastomer, a petroleum resin, a tackifier resin and a plasticizer, and which has a certain initial strength by formulation adjustment, and which is inferior in performance under severe climatic conditions such as high temperature and high humidity resistance due to the absence of chemical crosslinking in the system, as shown in table 1, comparative example 2 has a thrust 48-hour final strength, a thrust 85 ℃/85 RH72 hour final strength and a thrust 60 ℃/90 RH72 hour final strength which are far apart from those of examples 1 to 7, i.e., both the curing strength and the high temperature and high humidity resistance are inferior, and is particularly not suitable for use in a severe environment of high temperature and high humidity.

The comparative example 3 directly mixes the traditional SBR hot melt adhesive with the moisture reactive polyurethane polymer, and because the polymer obtained by the reaction of the general active hydrogen compound and isocyanate has higher polarity and has larger polarity difference with the important component SBC rubber polymer in the traditional SBR, a stable system can not be obtained by simply mixing the two polymers together, and a stable system product can not be formed in the comparative example 3, so that a layered state appears and subsequent related tests can not be carried out.

In the invention, the diene liquid rubber with at least one end group having an active hydrogen functional group is utilized to effectively realize the reaction of an active hydrogen compound and isocyanate so that the active hydrogen compound is matched with the SBC rubber polymer in polarity, and the stability of the system is effectively ensured, as can be seen from the test data of examples 1-7:

1. the initial strength is much higher than that of the conventional PUR moisture-curable adhesive system, and the final strength, duPont falling ball impact and high temperature and high humidity resistance of examples 1-3 and 6 are almost the same as those of the conventional PUR moisture-curable adhesive system, while examples 4, 5 and 7 have a loss of the final strength at 85 ℃/85 RH72 hour, 60 ℃/90 RH72 hour, compared with the conventional PUR moisture-curable adhesive system, in spite of the fact that the final strength Mpa at 48 hours of thrust, the DuPont falling ball impact after 48 hours, the final strength performance at 85 ℃/85 ℃ RH72 hour, and the final strength performance at 60 ℃/90 RH72 hour are both sufficient to meet the environmental requirements for viscosity and high temperature and high humidity resistance;

2. thrust final strength Mpa at 48 hours, duPont drop impact after 48 hours, 85 ℃/85% RH72 hour final strength, 60 ℃/90 RH72 hour final strength and other parameters are much higher than those of the traditional SBR rubber type hot melt adhesive system, and the performance is substantially improved;

3. the system has good stability, the viscosity, the initial strength, the DuPont falling ball impact property and the high-temperature and high-humidity strength meet higher requirements, the whole system is stable and balanced in performance, and the initial strength, the final strength and the strength under the high-temperature and high-humidity conditions are balanced, so that the product obtained by the method is wide in application range and good in stability.

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, therefore all equivalent technical solutions should also fall into the scope of the present invention, and should be defined by the claims.

Claims (10)

1. A moisture reactive rubber hot melt adhesive is characterized by comprising the following components in parts by weight:

2. the moisture-reactive rubber hot melt adhesive of claim 1, wherein the SBC rubber polymer is one or more of styrene-isoprene-styrene, styrene-butadiene-styrene, styrene-isoprene-butadiene, styrene-ethylene-butylene-styrene, styrene-ethylene-propylene-styrene, styrene-ethylene-butylene-styrene, maleic-anhydrized styrene-ethylene-butylene-styrene, vinyl-terminated styrene-butadiene-styrene.

3. A moisture-reactive rubber hot-melt adhesive as claimed in claim 1, wherein said diene-based liquid rubber is one or more of polybutadiene rubber and polyisoprene rubber.

4. A moisture-reactive rubber hot melt adhesive as in claim 1, wherein: the active hydrogen functional group is selected from one or more of amino, hydroxyl and carboxyl functional groups.

5. The moisture-reactive rubber hot-melt adhesive according to claim 1, wherein the synthetic resin is one or more of an unhydrogenated aliphatic petroleum resin, an unhydrogenated aromatic petroleum resin, an unhydrogenated aliphatic/aromatic copolymer resin, an unhydrogenated styrene resin, a hydrogenated aliphatic petroleum resin, a hydrogenated aromatic petroleum resin, a hydrogenated aliphatic/aromatic copolymer resin, and a hydrogenated styrene resin.

6. A moisture-reactive rubber hot melt adhesive as in claim 1, wherein said tackifying resin is one or more of rosin, rosin derivatives, terpene resins, and terpene resin derivatives.

7. A moisture-reactive rubber hot melt adhesive as in claim 1, wherein said plasticizer is a naphthenic oil.

8. A moisture-reactive rubber hot melt adhesive as in claim 1, wherein said antioxidant is selected from at least one of pentaerythrityl tetrakis [ β - (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ], tris [2, 4-di-t-butylphenyl ] phosphite and n-octadecyl β - (3, 5-di-t-butyl-4-hydroxyphenyl) propionate.

9. A moisture-reactive rubber hot melt adhesive as in claim 1, wherein said isocyanate is one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate trimer, dicyclohexylmethane diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, L-lysine triisocyanate and polymethylene polyphenyl polyisocyanate.

10. A method of preparing a moisture-reactive rubber hot melt adhesive as in claim 1, wherein said method of preparing a moisture-reactive rubber hot melt adhesive comprises the steps of:

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

s2: adding the SBC rubber polymer prepared in the S1, a plasticizer and an antioxidant into a reactor, heating to 140-170 ℃, continuously stirring until all materials in the reactor are molten, and then reacting stably for 15min;

s3: adding the diene liquid rubber, the tackifying resin and the synthetic resin which are prepared in the step S1 and at least one end group of which has an active hydrogen functional group into the reactor while stirring at the temperature of 140-170 ℃, vacuumizing and stirring for 120min, adding the isocyanate prepared in the step S1 at the temperature of 140-170 ℃, reacting for 60min, and defoaming.