Preparation method of antibacterial and mildew-proof sealant, air conditioner evaporator and air conditioner

Abstract

The invention provides a preparation method of antibacterial and mildew-proof sealing cement, an air conditioner evaporator and an air conditioner, belongs to the technical field of sealing materials, and can solve the problem that the antibacterial and mildew-proof functions of a sealing material of an existing air conditioner evaporator fail in a short time. The preparation method of the antibacterial and mildewproof sealing cement comprises the steps of preparing the modified guanidine antibacterial and mildewproof agent and preparing the antibacterial and mildewproof sealing cement strip. The antibacterial and mildew-proof sealing cement can be applied to an air conditioner evaporator, has a long-acting antibacterial and mildew-proof function, inhibits the mildew-proof problem in the use process, and avoids generation of peculiar smell and influence on comfort.

Description

Technical Field

[0001] The invention belongs to the technical field of sealing materials, and in particular relates to a preparation method of antibacterial and mildew-proof sealing putty, an air-conditioning evaporator and an air-conditioning. Background Art

[0002] The air conditioner evaporator uses the liquid low-temperature refrigerant to evaporate easily under low pressure, turn into steam and absorb the heat of the cooled medium to achieve the purpose of refrigeration. The air conditioner evaporator is made of a bent U-shaped tube that passes through the fins, and is expanded and welded. Due to the structural design characteristics of the hanging machine, there is a physical gap between the two folded structures of the hanging machine evaporator at the connection of adjacent pipes. In order to prevent water leakage, it is necessary to add sealing materials such as sealing putty, plastic sealing strips (blocks), sealing card strips, hot melt adhesives, etc. between the gaps. Although the sealing problem can be solved to a certain extent by adding sealing materials, the internal environment of the air conditioner will be relatively humid during the cooling stage, and water molecules will partially remain on the evaporator including the surface of the sealing material. The humid surface of the sealing material creates conditions for the growth of mold, which not only threatens human health, but also produces odor and causes discomfort to the human body.

[0003] At present, the above problem is usually solved by adding antibacterial and mildew-proof agents to polymers to prepare sealing materials. The antibacterial and mildew-proof agents added to polymers play an antibacterial and mildew-proof role by migrating to the surface of the polymer. However, since the molecular weight of conventional antibacterial and mildew-proof agents is small, the rate of migration to the surface of the polymer is fast, and the antibacterial and mildew-proofing failure occurs in a short time. Therefore, providing a sealing material with long-term antibacterial and mildew-proofing function is a problem that technicians in this field need to solve urgently. Summary of the invention

[0004] The present invention aims to solve the problem that the antibacterial and mildew-proof functions of the existing sealing materials for air-conditioning evaporators lose effectiveness in a short period of time, and proposes a sealing putty with long-lasting antibacterial and mildew-proof functions. The antibacterial and mildew-proof agent is grafted and polymerized with a polymer matrix material into a whole by a chemical grafting reaction method, and the migration rate of the antibacterial and mildew-proof agent is controlled, so that the sealing putty has a long-lasting antibacterial and mildew-proof function, and mildew-proof problems during use are suppressed, and odor is avoided to affect comfort.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: a method for preparing an antibacterial and mildew-proof sealing putty, comprising the following steps:

[0006] (1) Preparation of modified guanidine antibacterial and antifungal agents:

[0007] The butyl latex and the graft modifier are stirred and mixed evenly, the initiator is slowly added, and the stirring is continued for a certain period of time to obtain an intermediate product;

[0008] Slowly add guanidine salt antibacterial and antifungal agent to the intermediate product, keep stirring, and continuously discharge the generated water. After the reaction is complete, let it stand, remove the upper liquid, and transfer the bottom product to a centrifuge tube;

[0009] Add acetone to the centrifuge tube and stir evenly, then centrifuge it and remove the supernatant;

[0010] The product obtained by centrifugation is dried in a vacuum environment to obtain a modified guanidine antibacterial and antifungal agent;

[0011] (2) Preparation of antibacterial and mildew-proof sealing adhesive strips:

[0012] After the butyl rubber block is pretreated, it is added into an internal mixer together with polyisobutylene and antioxidant for mixing. When the butyl rubber becomes muddy, tackifying resin, filler and coupling agent are added for further mixing.

[0013] After cooling the internal mixer, the modified guanidine antibacterial and antifungal agent and stearic acid are added, and the mixing is continued to obtain a uniformly mixed material;

[0014] The uniformly mixed materials are transferred out, arranged into round strips, cooled, added into a rubber extruder and extruded into strips to obtain antibacterial and mildew-proof sealing adhesive strips.

[0015] Preferably, the butyl latex is 80-100g, the guanidine salt antibacterial and mildewproof agent is 25-40g, the graft modifier is 25-30g, the initiator is 1-3g, and the acetone is 10-20mL; the butyl rubber is 80-100g, the modified guanidine antibacterial and mildewproof agent is 3-8g, the tackifying resin is 15-25g, the polyisobutylene is 40-60g, the filler is 150-200g, the antioxidant is 1-3g, the stearic acid is 1.5-3g, and the odorless coupling agent is 3-5g. It can be understood that, according to actual conditions, those skilled in the art can adjust the mass of each component within the above range. For example, the amount of butyl latex can be 80g, 85g, 90g, 95g, 100g or any value within the above range, the amount of guanidine salt antibacterial and mildew preventive can be 25g, 30g, 35g, 40g or any value within the above range, the amount of graft modifier can be 25g, 26g, 27g, 28g, 29g, 30g or any value within the above range, the amount of initiator can be 1g, 1.5g, 2g, 2.5g, 3g or any value within the above range, the amount of acetone can be 10mL, 12mL, 14mL, 16mL, 18mL, 20mL or any value within the above range, the amount of butyl rubber can be 80g, 85g, 90g, 95g, 100g or any value within the above range, the modified guanidine antibacterial and mildew preventive The amount of can be 3g, 4g, 5g, 6g, 7g, 8g or any value within the above range, the amount of tackifying resin can be 15g, 16g, 17g, 18g, 19g, 20g, 21g, 22g, 23g, 24g, 25g or any value within the above range, the amount of polyisobutylene can be 40g, 45g, 50g, 55g, 60g or any value within the above range, the amount of filler can be 150 The amount of the antioxidant can be 1g, 1.5g, 2g, 2.5g, 3g or any point in the above range, the amount of stearic acid can be 1.5g, 2g, 2.5g, 3g or any point in the above range, and the amount of the odorless coupling agent can be 3g, 3.5g, 4g, 4.5g, 5g or any point in the above range.

[0016] Preferably, the total solid content of the butyl latex is 50%-55%, and the Mooney viscosity is 17-24MU.

[0017] Preferably, the guanidine salt antibacterial and antifungal agent is at least one of polyhexamethyleneguanidine hydrochloride and polyhexamethylene biguanidine hydrochloride.

[0018] Preferably, the graft modifier is maleic anhydride or glycidyl methacrylate; and the initiator is at least one of an azo initiator and an organic peroxide initiator.

[0019] Preferably, the number average molecular weight of the polyisobutylene is 1000-2500.

[0020] Preferably, the tackifying resin is at least one of coumarone-indene resin, C5 resin, C9 resin, and DCPD resin; the filler is at least one of clay, kaolin, calcium powder, talcum powder, mica powder, and carbon black; and the antioxidant is at least one of amine antioxidants, phenolic antioxidants, phosphite antioxidants, and heterocyclic antioxidants.

[0021] Preferably, the odorless coupling agent is a titanate coupling agent.

[0022] Another aspect of the present invention provides an air-conditioning evaporator, which uses the antibacterial and mildew-proof sealing putty obtained by the above preparation method as a sealing material.

[0023] The present invention also provides an air conditioner, comprising the air conditioner evaporator.

[0024] Compared with the prior art, the advantages and positive effects of the present invention are as follows: the present invention adopts a chemical grafting reaction method to graft the antibacterial and mildew-proof agent onto the polymer matrix material to form a whole, controls the migration rate of the antibacterial and mildew-proof agent, enables the sealing putty to have a long-lasting antibacterial and mildew-proof function, inhibits mildew-proof problems during use, avoids the generation of odor, and affects comfort. DETAILED DESCRIPTION

[0025] In order to be able to understand the characteristics and technical contents of the embodiments of the present invention in more detail, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the embodiments described below are only part of the embodiments of the present invention, rather than all the embodiments of the present invention. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection requested by the present invention.

[0026] The embodiment of the present invention provides a method for preparing an antibacterial and mildew-proof sealing putty, an air conditioner evaporator and an air conditioner. The method for preparing the antibacterial and mildew-proof sealing putty of the present invention includes the preparation of a modified guanidine antibacterial and mildew-proof agent and the preparation of an antibacterial and mildew-proof sealing putty, wherein the modified guanidine antibacterial and mildew-proof agent includes the following raw materials: 80-100g of butyl latex, 25-40g of a guanidine salt antibacterial and mildew-proof agent, 25-30g of a grafted modifier, 1-3g of an initiator, and 10-20mL of acetone. The total solid content of butyl latex is 50%-55%, and the Mooney viscosity is 17-24MU; the guanidine salt antibacterial and mildew-proof agent is at least one of polyhexamethyleneguanidine hydrochloride (PHMG) and polyhexamethylene biguanide hydrochloride (PHMB); the grafting modifier is maleic anhydride or glycidyl methacrylate; the initiator is at least one of an azo initiator and an organic peroxide initiator, and the preferred initiator is azobisisobutyronitrile (AIBN) and dibenzoyl peroxide (BPO).

[0027] The preparation method of the modified guanidine antibacterial and antifungal agent of the present invention comprises the following steps:

[0028] Weigh butyl latex and graft modifier, stir and mix them evenly at high speed, heat to 50-80°C, slowly add initiator, and continue stirring for 5-7h to obtain an intermediate product;

[0029] After the intermediate product is cooled to 25-30°C, slowly add the guanidine salt antibacterial and antifungal agent, continue stirring, and continuously discharge the generated water. After the reaction is complete, let it stand, remove the upper liquid, and transfer the bottom product to a centrifuge tube;

[0030] Add acetone to the centrifuge tube and stir evenly, then put it into the centrifuge, centrifuge at 2000-2500 rpm for 3-10 minutes, remove the supernatant, and repeat the above steps 3-5 times;

[0031] The product obtained by centrifugation is dried in a vacuum environment at 25-30° C. for 8-10 hours to obtain a modified guanidine antibacterial and antifungal agent.

[0032] In the preparation method of the modified guanidine antibacterial and antifungal agent of the present invention, when the grafting modifier is maleic anhydride, the grafting modification reaction equation is as follows:

[0033]

[0034] The antibacterial and mildewproof sealing glue of the present invention comprises the following raw materials: 80-100g of butyl rubber, 3-8g of modified guanidine antibacterial and mildewproof agent, 15-25g of tackifying resin, 40-60g of polyisobutylene, 150-200g of filler, 1-3g of antioxidant, 1.5-3g of stearic acid, and 3-5g of odorless coupling agent, wherein the number average molecular weight of polyisobutylene is 1000-2500; the tackifying resin is coumarone-indene resin, C5 resin, C9 resin, DCPD Resin, preferably the tackifying resin is C5 tackifying resin or C9 tackifying resin; the filler is clay, kaolin, calcium powder, talc, mica powder, carbon black, etc., preferably clay and kaolin; the antioxidant is an amine antioxidant, a phenolic antioxidant, a phosphite antioxidant, a heterocyclic antioxidant, etc., preferably the antioxidant is an amine antioxidant, such as antioxidant RD and antioxidant 4020; the odorless coupling agent is a titanate coupling agent, such as GR-101, GR-102, and GR-300.

[0035] The preparation method of the antibacterial and mildew-proof sealing glue of the present invention comprises the following steps:

[0036] After the butyl rubber block is processed into flakes on an open mill, it is added together with polyisobutylene and antioxidant into an internal mixer or kneader at a temperature of 60-100°C and kneaded for 20-40 minutes. When the butyl rubber becomes muddy, tackifying resin, filler and coupling agent are added and kneaded for another 10-20 minutes to ensure that the filler powder is evenly dispersed without agglomerated powder.

[0037] Stop heating, cool the internal mixer or kneader to 80°C, then add the modified guanidine antibacterial and antifungal agent and stearic acid, and continue mixing for 5-10 minutes to ensure that the modified guanidine antibacterial and antifungal agent is evenly dispersed to obtain a uniformly mixed material;

[0038] The uniformly mixed material is transferred out, arranged into round strips, cooled to 20-25° C., and then the round strips are added into a rubber extruder and extruded into strips through an extrusion die to obtain antibacterial and mildew-proof sealing adhesive strips.

[0039] The present invention also provides an air-conditioning evaporator, using the antibacterial and mildew-proof sealing putty prepared by the above method as a sealing material.

[0040] The present invention also provides an air conditioner, comprising the air conditioner evaporator.

[0041] In order to more clearly and in detail introduce the antibacterial and mildew-proof sealing putty provided by the embodiments of the present invention, it will be described below in conjunction with specific embodiments.

[0042] Example 1

[0043] Example 1 The method for preparing the antibacterial and mildew-proof sealing putty includes the preparation of a modified guanidine antibacterial and mildew-proof agent and the preparation of the antibacterial and mildew-proof sealing putty.

[0044] (1) Preparation of modified guanidine antibacterial and antifungal agents

[0045] Raw materials: 100 g of butyl latex, 40 g of polyhexamethylene biguanide hydrochloride (PHMB) as guanidine salt antibacterial and mildew-proof agent, 30 g of maleic anhydride as graft modifier, 2 g of azobisisobutyronitrile (AIBN) as initiator, and 20 mL of acetone, wherein the total solid content of butyl latex is 50% and the Mooney viscosity is 17 MU;

[0046] The preparation method comprises the following steps:

[0047] Weigh butyl latex and maleic anhydride, mix and stir at high speed, heat to 80°C, add AIBN, and continue stirring for 5 hours to obtain the intermediate product IIR-g-MAH;

[0048] After cooling to 25°C, slowly add PHMB antibacterial agent, continue stirring, and continuously discharge the generated water. After the reaction is complete, let it stand, remove the upper liquid, and transfer the bottom product to a centrifuge tube;

[0049] Add acetone to the centrifuge tube and stir evenly, then put it into the centrifuge, centrifuge at 2500 rpm for 10 min, remove the supernatant, and repeat the above centrifugation operation 5 times;

[0050] The product obtained by centrifugation was dried in a vacuum environment at 30° C. for 10 h to obtain butyl rubber grafted maleic anhydride modified PHMB antibacterial and antifungal agent.

[0051] (2) Preparation of antibacterial and mildew-proof sealing adhesive strips

[0052] Raw materials: 100g butyl rubber, 8g butyl rubber grafted maleic anhydride modified PHMB antibacterial and mildewproof agent, 25g C9 tackifying resin, 60g polyisobutylene, 200g clay as filler, 2g antioxidant RD as antioxidant, 3g stearic acid, 5g odorless coupling agent titanate coupling agent GR-101, wherein the number average molecular weight of polyisobutylene is 2500;

[0053] The preparation method comprises the following steps:

[0054] After the butyl rubber block is thinly processed into sheets on an open mill, it is added together with polyisobutylene and antioxidant RD into an internal mixer or kneader at a temperature of 100°C and kneaded for 40 minutes. When the butyl rubber state becomes muddy, C9 tackifying resin, clay, and titanate coupling agent GR-101 are added and kneaded for another 20 minutes to ensure that the clay powder is evenly dispersed without agglomerated powder;

[0055] Stop heating, cool the internal mixer or kneader to 80°C, add butyl rubber grafted maleic anhydride modified PHMB antibacterial and mildew preventer, and stearic acid, and continue mixing for 10 minutes to ensure that the butyl rubber grafted maleic anhydride modified guanidine antibacterial and mildew preventer is evenly dispersed;

[0056] The uniformly mixed material is transferred out, arranged into round strips, cooled to 25° C., and then the round strips are added into a rubber extruder and extruded into strips through an extrusion die to obtain antibacterial and mildew-proof sealing adhesive strips.

[0057] Example 2

[0058] Example 2 The method for preparing the antibacterial and mildew-proof sealing putty includes the preparation of a modified guanidine antibacterial and mildew-proof agent and the preparation of the antibacterial and mildew-proof sealing putty.

[0059] (1) Preparation of modified guanidine antibacterial and antifungal agents

[0060] Raw materials: 100 g of butyl latex, 25 g of polyhexamethyleneguanidine hydrochloride (PHMG) as guanidine salt antibacterial and mildew-proof agent, 30 g of maleic anhydride as graft modifier, 2 g of azobisisobutyronitrile (AIBN) as initiator, and 20 mL of acetone, wherein the total solid content of butyl latex is 55% and the Mooney viscosity is 24 MU;

[0061] The preparation method comprises the following steps:

[0062] Weigh butyl latex and maleic anhydride, stir and mix them evenly at high speed, heat to 80°C, add initiator AIBN, and continue stirring for 7 hours to obtain the intermediate product IIR-g-MAH;

[0063] After cooling to 30°C, slowly add PHMG antibacterial agent, continue stirring, and continuously discharge the generated water. After the reaction is complete, let it stand, remove the upper liquid, and transfer the bottom product to a centrifuge tube;

[0064] Add acetone to the centrifuge tube and stir evenly, then put it into the centrifuge, centrifuge at 2500 rpm for 10 min, remove the supernatant, and repeat the above centrifugation operation 3 times;

[0065] The obtained product was dried in a vacuum environment at 30° C. for 10 h to obtain a butyl rubber grafted maleic anhydride modified PHMG antibacterial and antifungal agent.

[0066] (2) Preparation of antibacterial and mildew-proof sealing adhesive strips

[0067] Raw materials: 100g butyl rubber, 5g butyl rubber grafted maleic anhydride modified PHMG antibacterial and mildewproof agent, 20g C9 tackifying resin, 60g polyisobutylene, 200g kaolin as filler, 2g antioxidant 4020, 3g stearic acid, 5g odorless coupling agent titanate coupling agent GR-102, wherein the number average molecular weight of polyisobutylene is 2000;

[0068] The preparation method comprises the following steps:

[0069] After the butyl rubber block is thinned into sheets on an open mill, it is added together with polyisobutylene and antioxidant 4020 into an internal mixer or kneader at a temperature of 100°C and kneaded for 40 minutes. When the butyl rubber state becomes muddy, C9 tackifying resin, kaolin, and titanate coupling agent GR-102 are added and kneaded for another 20 minutes to ensure that the kaolin powder is evenly dispersed without agglomerated powder;

[0070] Stop heating, cool the internal mixer or kneader to 80°C, add butyl rubber grafted maleic anhydride modified PHMG antibacterial and mildew preventer, and stearic acid, and continue mixing for 10 minutes to ensure that the butyl rubber grafted maleic anhydride modified guanidine antibacterial and mildew preventer is evenly dispersed;

[0071] The uniformly mixed material is transferred out, arranged into round strips, cooled to 25° C., and then the round strips are added into a rubber extruder and extruded into strips through an extrusion die to obtain antibacterial and mildew-proof sealing adhesive strips.

[0072] Example 3

[0073] The preparation method of the antibacterial and mildew-proof sealing putty in Example 3 includes the preparation of a modified guanidine antibacterial and mildew-proof agent and the preparation of an antibacterial and mildew-proof sealing putty.

[0074] (1) Preparation of modified guanidine antibacterial and antifungal agents

[0075] Raw materials: 100 g of butyl latex, 35 g of polyhexamethylene biguanide hydrochloride (PHMB) as guanidine salt antibacterial and mildew-proof agent, 30 g of maleic anhydride as graft modifier, 2.5 g of dibenzoyl peroxide (BPO) as initiator, and 20 mL of acetone, wherein the total solid content of butyl latex is 50% and the Mooney viscosity is 24 MU;

[0076] The preparation method comprises the following steps:

[0077] Weigh butyl latex and maleic anhydride, stir and mix them evenly at high speed, heat to 80°C, add initiator BPO, and continue stirring for 5 hours to obtain the intermediate product IIR-g-MAH;

[0078] After cooling to 25°C, slowly add PHMB antibacterial agent, continue stirring, and continuously discharge the generated water. After the reaction is complete, let it stand, remove the upper liquid, and transfer the bottom product to a centrifuge tube;

[0079] Add acetone to the centrifuge tube and stir evenly, then put it into the centrifuge, centrifuge at 2500 rpm for 10 min, remove the supernatant, and repeat the above centrifugation operation 3 times;

[0080] The obtained product was dried in a vacuum environment at 30° C. for 10 h to obtain a butyl rubber grafted maleic anhydride modified PHMB antibacterial and antifungal agent.

[0081] (2) Preparation of antibacterial and mildew-proof sealing adhesive strips

[0082] Raw materials: 100g butyl rubber, 5g butyl rubber grafted maleic anhydride modified PHMB antibacterial and mildewproof agent, 20g coumarone-indene tackifying resin, 60g polyisobutylene, 200g clay as filler, 2g antioxidant RD as antioxidant, 3g stearic acid, 5g odorless coupling agent titanate coupling agent GR-101, wherein the number average molecular weight of polyisobutylene is 2500;

[0083] The preparation method comprises the following steps:

[0084] After the butyl rubber block is thinned into sheets on an open mill, it is added together with polyisobutylene and antioxidant RD into an internal mixer or kneader at a temperature of 100°C and kneaded for 40 minutes. When the butyl rubber becomes muddy, coumarone-indene tackifying resin, clay, and titanate coupling agent GR-101 are added and kneaded for another 20 minutes to ensure that the clay powder is evenly dispersed without agglomerated powder.

[0085] Stop heating, cool the internal mixer or kneader to 80°C, add butyl rubber grafted maleic anhydride modified PHMB antibacterial and mildew preventer, and stearic acid, and continue mixing for 10 minutes to ensure that the butyl rubber grafted maleic anhydride modified PHMB antibacterial and mildew preventer is evenly dispersed;

[0086] The uniformly mixed material is transferred out, arranged into round strips, cooled to 25° C., and then the round strips are added into a rubber extruder and extruded into strips through an extrusion die to obtain antibacterial and mildew-proof sealing adhesive strips.

[0087] Example 4

[0088] Example 4 The method for preparing the antibacterial and mildew-proof sealing putty includes the preparation of a modified guanidine antibacterial and mildew-proof agent and the preparation of the antibacterial and mildew-proof sealing putty.

[0089] (1) Preparation of modified antibacterial and antifungal additives

[0090] Raw materials: 100g butyl latex, guanidine salt antibacterial and antifungal agent is polyhexamethyleneguanidine hydrochloride (PHMG)

[0091] 35g, the graft modifier is glycidyl methacrylate 30g, the initiator is dibenzoyl peroxide (BPO) 2.5g, acetone 20mL, wherein the total solid content of butyl latex is 55%, and the Mooney viscosity is 24MU;

[0092] The preparation method comprises the following steps:

[0093] Weigh butyl latex and glycidyl methacrylate, mix them at high speed and stir them evenly, add initiator BPO after heating to 80°C, and continue stirring for 7 hours to obtain the intermediate product IIR-g-GMA;

[0094] After cooling to 30°C, slowly add PHMG antibacterial agent, continue stirring, and continuously discharge the generated water. After the reaction is complete, let it stand, remove the upper liquid, and transfer the bottom product to a centrifuge tube;

[0095] Add acetone to the centrifuge tube and stir evenly, then put it into the centrifuge, centrifuge at 2500 rpm for 10 min, remove the supernatant, and repeat the above centrifugation operation 3 times;

[0096] The product obtained by centrifugation was dried in a vacuum environment at 30° C. for 10 h to obtain a butyl rubber grafted glycidyl methacrylate modified PHMG antibacterial and antifungal agent.

[0097] (2) Preparation of antibacterial and mildew-proof sealing adhesive strips

[0098] Raw materials: 100g butyl rubber, 5g butyl rubber grafted glycidyl methacrylate modified PHMG antibacterial and mildewproof agent, 20g DCPD tackifying resin, 60g polyisobutylene, 200g kaolin as filler, 2g antioxidant RD as antioxidant, 3g stearic acid, 5g odorless coupling agent titanate coupling agent GR-300, wherein the number average molecular weight of polyisobutylene is 2500;

[0099] The preparation method comprises the following steps:

[0100] After the butyl rubber block is thinly processed into flakes on an open mill, it is added together with polyisobutylene and antioxidant RD into an internal mixer or kneader at a temperature of 100°C and kneaded for 40 minutes. When the butyl rubber state becomes muddy, DCPD tackifying resin, kaolin, and titanate coupling agent GR-300 are added and kneaded for another 20 minutes to ensure that the kaolin powder is evenly dispersed without agglomerated powder;

[0101] Stop heating, cool the internal mixer or kneader to 80°C, add butyl rubber grafted glycidyl methacrylate modified PHMG antibacterial and mildew preventer, and stearic acid, and continue mixing for 10 minutes to ensure that the butyl rubber grafted glycidyl methacrylate modified PHMG antibacterial and mildew preventer is evenly dispersed;

[0102] The uniformly mixed material is transferred out, arranged into round strips, cooled to 25° C., and then the round strips are added into a rubber extruder and extruded into strips through an extrusion die to obtain antibacterial and mildew-proof sealing adhesive strips.

[0103] Comparative Example 1

[0104] Comparative Example 1 The preparation method of the antibacterial and mildew-proof sealing putty includes the preparation of the antibacterial and mildew-proof agent and the preparation of the antibacterial and mildew-proof sealing putty.

[0105] (1) Preparation of modified antibacterial and antifungal agents

[0106] The raw materials are the same as those in Example 1, including: 100 g of butyl latex, 40 g of polyhexamethylene biguanide hydrochloride (PHMB) as a guanidine salt antibacterial and mildew-proof agent, 30 g of maleic anhydride as a graft modifier, 2 g of azobisisobutyronitrile (AIBN) as an initiator, and 20 mL of acetone, wherein the total solid content of the butyl latex is 50% and the Mooney viscosity is 17 MU;

[0107] The preparation method comprises the following steps:

[0108] Weigh the raw materials butyl latex, maleic anhydride, PHMB, and initiator AIBN, add them into a beaker in sequence, and stir for 7 hours to obtain a mixture 1;

[0109] The mixture 1 was transferred to a centrifuge tube, acetone was added and stirred evenly, and then the mixture was placed in a centrifuge and centrifuged at 2500 rpm for 10 min. The supernatant was removed and the above centrifugation operation steps were repeated 5 times. The product obtained by centrifugation was dried in a vacuum environment at 30°C for 10 h to obtain the mixture 2, that is, the modified antibacterial and mildew-proof agent.

[0110] (2) Preparation of antibacterial and mildew-proof sealing adhesive strips

[0111] Raw materials: 100 g of butyl rubber, 8 g of the modified antibacterial and mildewproof agent obtained in step (1), 25 g of C9 tackifying resin, 60 g of polyisobutylene, 200 g of clay as filler, 2 g of antioxidant RD as antioxidant, 3 g of stearic acid, 5 g of titanate coupling agent GR-101 as odorless coupling agent, wherein the number average molecular weight of polyisobutylene is 2500;

[0112] The preparation method comprises the following steps:

[0113] After the butyl rubber block is thinly processed into sheets on an open mill, it is added together with polyisobutylene and antioxidant RD into an internal mixer or kneader at a temperature of 100°C and kneaded for 40 minutes. When the butyl rubber state becomes muddy, C9 tackifying resin, clay, and titanate coupling agent GR-101 are added and kneaded for another 20 minutes to ensure that the clay powder is evenly dispersed without agglomerated powder;

[0114] Stop heating, cool the internal mixer or kneader to 80°C, add the modified antibacterial and antifungal agent and stearic acid, and continue mixing for 10 minutes to ensure uniform dispersion;

[0115] The uniformly mixed material is transferred out, arranged into round strips, cooled to 25° C., and then the round strips are added into a rubber extruder and extruded into strips through an extrusion die to obtain antibacterial and mildew-proof sealing adhesive strips.

[0116] Comparative Example 2

[0117] Comparative Example 2 The method for preparing the antibacterial and mildew-proof sealing putty includes the preparation of a modified antibacterial and mildew-proof agent and the preparation of the antibacterial and mildew-proof sealing putty.

[0118] (1) Preparation of modified antibacterial and antifungal agents

[0119] The raw materials are the same as those in Example 4, including: 100 g of butyl latex, 35 g of polyhexamethylene guanidine hydrochloride (PHMG) as a guanidine salt antibacterial and mildew-proof agent, 30 g of glycidyl methacrylate as a graft modifier, 2.5 g of dibenzoyl peroxide (BPO) as an initiator, and 20 mL of acetone, wherein the total solid content of the butyl latex is 55% and the Mooney viscosity is 24 MU;

[0120] The preparation method comprises the following steps:

[0121] Weigh the raw materials butyl latex, glycidyl methacrylate, PHMG, and initiator BPO and add them into a beaker in sequence, and stir for 7 hours to obtain a mixture 1;

[0122] The mixture 1 was transferred to a centrifuge tube, acetone was added and stirred evenly, and then the mixture was placed in a centrifuge and centrifuged at 2500 rpm for 10 min. The supernatant was removed and the above centrifugation operation steps were repeated 5 times. The product obtained by centrifugation was dried in a vacuum environment at 30°C for 10 h to obtain the mixture 2, that is, the modified antibacterial and mildew-proof agent.

[0123] (2) Preparation of antibacterial and mildew-proof sealing adhesive strips

[0124] Raw materials: 100 g of butyl rubber, 5 g of the modified antibacterial and mildew-proof agent obtained in step (1), 20 g of C5 tackifying resin, 60 g of polyisobutylene, 200 g of kaolin as filler, 2 g of antioxidant RD as antioxidant, 3 g of stearic acid, and 5 g of titanate coupling agent GR-300 as odorless coupling agent.

[0125] The preparation method comprises the following steps:

[0126] After the butyl rubber block is thinned into flakes on an open mill, it is added together with polyisobutylene and antioxidant RD into an internal mixer or kneader at a temperature of 100°C and kneaded for 40 minutes. When the butyl rubber becomes muddy, C5 tackifying resin, kaolin and titanate coupling agent GR-300 are added and kneaded for another 20 minutes to ensure that the kaolin powder is evenly dispersed without agglomerated powder.

[0127] Stop heating, cool the internal mixer or kneader to 80°C, add the modified antibacterial and antifungal agent and stearic acid, and continue mixing for 10 minutes to ensure uniform dispersion;

[0128] The uniformly mixed material is transferred out, arranged into round strips, cooled to 25° C., and then the round strips are added into a rubber extruder and extruded into strips through an extrusion die to obtain antibacterial and mildew-proof rubber putty strips.

[0129] Comparative Example 3

[0130] The preparation method of the antibacterial and mildew-proof sealing putty of Comparative Example 3 includes the preparation of a modified guanidine antibacterial and mildew-proof agent and the preparation of an antibacterial and mildew-proof sealing putty.

[0131] (1) Preparation of modified guanidine antibacterial and antifungal agents

[0132] Raw materials: 100 g of butyl latex, 35 g of polyhexamethylene biguanide hydrochloride (PHMB) as guanidine salt antibacterial and mildew-proof agent, 30 g of maleic anhydride as graft modifier, 2.5 g of dibenzoyl peroxide (BPO) as initiator, and 20 mL of acetone, wherein the total solid content of butyl latex is 50% and the Mooney viscosity is 24 MU;

[0133] The preparation method comprises the following steps:

[0134] Weigh butyl latex and maleic anhydride, stir and mix them evenly at high speed, heat to 80°C, add initiator BPO, and continue stirring for 5 hours to obtain the intermediate product IIR-g-MAH;

[0135] After cooling to 25°C, slowly add PHMB antibacterial agent, continue stirring, and continuously discharge the generated water. After the reaction is complete, let it stand, remove the upper liquid, and transfer the bottom product to a centrifuge tube;

[0136] Add 20 mL of acetone to the centrifuge tube and stir evenly, then put it into a centrifuge and centrifuge it at 2500 rpm for 10 min. Remove the supernatant and repeat the above centrifugation operation 5 times.

[0137] The product obtained by centrifugation was dried in a vacuum environment at 30° C. for 10 h to obtain butyl rubber grafted maleic anhydride modified PHMB antibacterial and antifungal agent.

[0138] (2) Preparation of antibacterial and mildew-proof sealing adhesive strips

[0139] Raw materials: 100g butyl rubber, 5g butyl rubber grafted maleic anhydride modified PHMB antibacterial and mildew-proof agent, 20g C9 tackifying resin, 60g polyisobutylene, 200g clay, 2g antioxidant RD, 3g stearic acid, and 5g odorless coupling agent titanate coupling agent.

[0140] The preparation method comprises the following steps:

[0141] After the butyl rubber block is thinned into sheets on an open mill, it is added together with polyisobutylene and antioxidant RD into an internal mixer or kneader at a temperature of 100°C and kneaded for 40 minutes. When the butyl rubber state becomes muddy, C9 tackifying resin, clay, titanate coupling agent, butyl rubber grafted maleic anhydride modified PHMB antibacterial and mildew-proof agent, and stearic acid are added and kneaded for 30 minutes;

[0142] The mixed material is transferred out, arranged into round strips, cooled to 25° C., and then the round strips are added into a rubber extruder and extruded into strips through an extrusion die to obtain antibacterial and mildew-proof sealing adhesive strips.

[0143] Performance Testing

[0144] The antibacterial rate, mildew resistance grade and long-term antibacterial and mildew resistance of the antibacterial and mildew resistance sealant strips obtained in Examples 1-4 and Comparative Examples 1-3 were tested, and the test results are shown in Table 1. The antibacterial rate and mildew resistance grade of the test samples were tested in accordance with GB / T 21551.2-2010; the long-term antibacterial and mildew resistance test conditions were that the sealing adhesive strips were stored for 1000 hours at a temperature of 25°C and a humidity of 70%, and the antibacterial rate and mildew resistance grade of the test samples were tested in accordance with GB / T 21551.2-2010.

[0145] Table 1 Performance test table of antibacterial and mildew-proof sealing adhesive strips obtained from Examples 1-4 and Comparative Examples 1-3

[0146]

[0147] It can be seen from the above that Comparative Example 1 corresponds to Example 1, and Comparative Example 2 corresponds to Example 4, and the antibacterial and mildew-proofing agents in Comparative Example 1 and Comparative Example 2 are not grafted onto butyl rubber, the addition sequence of the antibacterial and mildew-proofing sealing putty strips in step (2) of Comparative Example 1 is the same as that in Example 1, and the addition sequence of the antibacterial and mildew-proofing sealing putty strips in step (2) of Comparative Example 2 is the same as that in Example 4. It can be seen from the data in Table 1 that the initial antibacterial and mildew-proofing effects of Comparative Examples 1 and 2 are not affected, and are not much different from the corresponding examples, but the long-term effects are significantly reduced. Comparative Example 3 corresponds to Example 3. Step (1) of Comparative Example 3 is the same as that of Example 3, and the antibacterial and mildew-proof agent is grafted onto the butyl rubber. It can be seen from the data in Table 1 that the long-term effectiveness of the antibacterial and mildew-proof sealing putty strip obtained in Comparative Example 3 is not affected, and the durability test results have little change from the initial ones. The order of adding materials for the preparation of the antibacterial and mildew-proof putty strip in step (2) of Comparative Example 3 is different from that in Example 3. In Comparative Example 3, the remaining raw materials are mixed together with the muddy butyl rubber. The difference in the above processes leads to poor dispersion effect of the grafted and modified antibacterial and mildew-proof agent in Comparative Example 3, and the initial antibacterial and mildew-proof effect of the prepared antibacterial and mildew-proof sealing putty strip is poor, which is significantly lower than that in Example 3.

[0148] Embodiments 1-3 adopt the technical scheme of the present invention, and graft the antibacterial and mildew-proof agent to the polymer matrix material into a whole through a chemical grafting reaction method, and control the migration rate of the antibacterial and mildew-proof agent, so that the obtained sealing putty not only has excellent initial antibacterial and mildew-proof effect, with an antibacterial rate of more than 99.9%, but also has a durability test with little change from the initial antibacterial rate and mildew-proof grade, and has long-lasting antibacterial and mildew-proof function.

[0149] Finally, it should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only the preferred feasible embodiments of the present invention, and the above-mentioned embodiments are only used to illustrate the technical scheme of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, modifications, evolutions and improvements made by ordinary technicians in this field to the technical scheme of the present invention should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing an antibacterial and mildew-proof sealing mortar, characterized in that: The following steps are involved: (1) Preparation of modified guanidine antibacterial and antifungal agents: The butyl latex and the graft modifier are stirred and mixed evenly, the initiator is slowly added, and the stirring is continued for a certain period of time to obtain an intermediate product; Slowly add a guanidine salt antibacterial and antifungal agent to the intermediate product, continue stirring, and continuously discharge the generated water. After the reaction is complete, let it stand, remove the upper layer of liquid, and transfer the bottom layer product to a centrifuge tube; Add acetone to the centrifuge tube and stir evenly, then centrifuge it and remove the supernatant; The product obtained by centrifugation is dried in a vacuum environment to obtain a modified guanidine antibacterial and antifungal agent; (2) Preparation of antibacterial and mildew-proof sealing adhesive strips: After the butyl rubber block is pretreated, it is added into an internal mixer together with polyisobutylene and antioxidant for mixing. When the butyl rubber becomes muddy, tackifying resin, filler and coupling agent are added for further mixing. After cooling the internal mixer, the modified guanidine antibacterial and antifungal agent and stearic acid are added, and mixing is continued to obtain a uniformly mixed material; The uniformly mixed materials are transferred out, arranged into round strips, cooled, added into a rubber extruder and extruded into strips to obtain antibacterial and mildew-proof sealing adhesive strips.

2. The method for preparing the antibacterial and mildew-proof sealing glue according to claim 1, characterized in that: The butyl latex is 80-100g, the guanidine salt antibacterial and mildew-proof agent is 25-40g, the graft modifier is 25-30g, the initiator is 1-3g, and the acetone is 10-20mL; the butyl rubber is 80-100g, the modified guanidine antibacterial and mildew-proof agent is 3-8g, the tackifying resin is 15-25g, the polyisobutylene is 40-60g, the filler is 150-200g, the antioxidant is 1-3g, the stearic acid is 1.5-3g, and the odorless coupling agent is 3-5g.

3. The method for preparing the antibacterial and mildew-proof sealing glue according to claim 2, characterized in that: The total solid content of the butyl latex is 50%-55%, and the Mooney viscosity is 17-24MU.

4. The method for preparing the antibacterial and mildew-proof sealing glue according to claim 2, characterized in that: The guanidine salt antibacterial and antifungal agent is at least one of polyhexamethyleneguanidine hydrochloride and polyhexamethylene biguanidine hydrochloride.

5. The method for preparing the antibacterial and mildew-proof sealing glue according to claim 2, characterized in that: The graft modifier is maleic anhydride or glycidyl methacrylate; the initiator is at least one of an azo initiator and an organic peroxide initiator.

6. The method for preparing the antibacterial and mildew-proof sealing glue according to claim 2, characterized in that: The number average molecular weight of the polyisobutylene is 1000-2500.

7. The method for preparing the antibacterial and mildew-proof sealing glue according to claim 2, characterized in that: The tackifying resin is at least one of coumarone-indene resin, C5 resin, C9 resin, and DCPD resin; the filler is at least one of clay, kaolin, calcium powder, talcum powder, mica powder, and carbon black; the antioxidant is at least one of amine antioxidants, phenolic antioxidants, phosphite antioxidants, and heterocyclic antioxidants.

8. The method for preparing the antibacterial and mildew-proof sealing glue according to claim 2, characterized in that: The odorless coupling agent is a titanate coupling agent.

9. An air-conditioning evaporator, using the antibacterial and mildew-proof sealing putty obtained by the preparation method according to any one of claims 1 to 8 as a sealing material.

10. An air conditioner comprising the air conditioner evaporator according to claim 9.

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