Hot melt adhesive for automobile interior and preparation method thereof

Abstract

The invention discloses a hot melt adhesive for automobile interior decoration, comprising the following raw materials in parts by weight: 30-50 parts of polycarbonate-based polyurethane, 15-30 parts of polyoxime urethane, 5-15 parts of a block copolymer of polystyrene-polyethylene-polypropylene-polystyrene, 1-9 parts of a composite tackifier, 0.5-5 parts of a plasticizer, and 0.1-3 parts of an anti-aging agent; the composite tackifier comprises a tackifier A and a tackifier B, which are compounded in a mass ratio of (0.5-1):(1-2); the tackifier A is obtained by a mixed reaction of silicon carbide, silicon dioxide and a coupling agent, and the tackifier B is a nano tackifier GY-2008; the hot melt adhesive prepared by the invention has rapid curing, strong bonding force, can be self-repaired at room temperature, has good durability, and has good application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of hot melt adhesives, and in particular to a hot melt adhesive for automobile interior decoration and a preparation method thereof. Background Art

[0002] At present, hot melt adhesive is widely used in various industries due to its excellent performance such as environmental protection and strong adhesion, including automotive interior, such as: car seat cushions, car steering wheel covers, carpets, trunk linings, and car air conditioning filters. Under normal circumstances, hot melt adhesives for automotive interior bonding need to meet the following requirements: First, the hot melt adhesive must be green and environmentally friendly, with stable performance and VOC content that meets industry standards. Secondly, the adhesion must be strong. For example, hot melt adhesives for bonding the lining of the trunk of a car must have strong adhesion and heat resistance of about 80 degrees. Thirdly, durability. As a means of transportation, cars are used frequently. Hot melt adhesives used for automotive interiors need to have good tensile resistance and durability to ensure that they are not easy to crack or fall off during use. However, cracking or debonding of plastic parts of automotive interiors occurs from time to time, which is related to the insufficient durability, adhesion or tensile resistance of hot melt adhesives.

[0003] Therefore, it is necessary to develop a hot melt adhesive for automotive interior with good comprehensive performance to solve the problem of debonding caused by insufficient bonding strength or insufficient tensile strength, and improve durability. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a hot melt adhesive with strong adhesion and good durability and a preparation method thereof. The hot melt adhesive not only has a fast curing speed, strong adhesion and good tensile strength, but also can self-repair at room temperature and can be recycled.

[0005] To this end, the present invention adopts the following technical solutions:

[0006] The present invention provides a hot melt adhesive for automobile interior decoration, comprising the following raw materials in parts by weight:

[0007] 30-50 parts of polycarbonate-based polyurethane;

[0008] 15-30 parts of polyoxime urethane;

[0009] 5-15 parts of a block copolymer of polystyrene-polyethylene-polypropylene-polystyrene;

[0010] 1-9 parts of composite tackifier;

[0011] Plasticizer 0.5-5 parts;

[0012] Anti-aging agent 0.1-3 parts;

[0013] The composite tackifier comprises tackifier A and tackifier B, which are compounded in a mass ratio of (0.5-1):(1-2); the tackifier A is obtained by a mixed reaction of silicon carbide, silicon dioxide and a coupling agent, and the tackifier B is a nano tackifier GY-2008.

[0014] Furthermore, the polyoxime urethane comprises the following components in parts by weight, and each component is obtained by reaction according to a proportion: 6-8 parts of polytetrahydrofuran, 20-40 parts of diacetyl oxime, 10-20 parts of 1,4-butanediol, 70-110 parts of toluene-3,5-diisocyanate and 0.5-1.5 parts of dibutyltin dilaurate.

[0015] Furthermore, the preparation method of the polyoxime urethane comprises the following steps:

[0016] (1) adding polytetrahydrofuran, dimethylglyoxime and 1,4-butanediol into a reaction vessel containing acetone, and stirring to mix uniformly;

[0017] (2) Then, toluene-3,5-diisocyanate and dibutyltin dilaurate are added, mixed evenly, poured into a polytetrafluoroethylene mold, and reacted in an oven at 40-60° C. for 1-6 hours, and dried to obtain a dynamically cross-linked polyoxime urethane.

[0018] Preferably, the mass ratio of silicon carbide, silicon dioxide and coupling agent in the tackifier A is (1-2):(1-2):(0.1-0.5).

[0019] Preferably, the coupling agent is an aminosilane coupling agent.

[0020] Preferably, the aminosilane coupling agent is selected from at least one of γ-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane.

[0021] Preferably, the antioxidant is 2,2-methylene-bis(4-ethyl-6-tert-butylphenol).

[0022] Preferably, the plasticizer is pentaerythritol tetravalerate.

[0023] Preferably, the polycarbonate-based polyurethane is obtained by prepolymerizing polycarbonate diol and isocyanate, followed by a small molecule chain extension reaction.

[0024] The present invention also provides a method for preparing hot melt adhesive for automobile interior, comprising the following steps: weighing raw materials according to a proportion, adding them into a twin-screw extruder, blending and extruding to obtain the hot melt adhesive for automobile interior.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The hot melt adhesive for automobile interior provided by the present invention is prepared by reacting polycarbonate-based polyurethane, polyoxime urethane, a block copolymer of polystyrene-polyethylene-polypropylene-polystyrene, a composite tackifier, a plasticizer and an antioxidant according to a ratio. Repeated experiments have shown that the hot melt adhesive has a fast curing speed, strong bonding ability, good tensile strength, and excellent properties of being strong and tough and capable of self-repairing at room temperature.

[0027] The polyoxime urethane provided by the present invention has a cross-linked chemical structure and certain thermoplasticity, and has good self-repair and remodeling properties, and the mechanical properties after remodeling are basically consistent with the initial mechanical properties. The combination of polycarbonate-based polyurethane and polyoxime urethane has good wettability to the substrate and is conducive to forming a strong adhesion.

[0028] The composite tackifier provided by the present invention is obtained by compounding two different adhesives. The composite adhesive can not only improve the bonding ability, but also improve the mechanical properties, increase the high temperature resistance, and enhance the aging resistance.

[0029] The hot melt adhesive provided by the present invention has good bonding performance, self-repairing ability, recyclability, good durability, excellent comprehensive performance, and has good application prospects in automobile interior decoration. DETAILED DESCRIPTION

[0030] Below by specific embodiment, the specific implementation mode of this explanation technical scheme is further described, these embodiments are for the detailed description of this technical scheme, rather than for limiting this technical scheme. Based on the embodiment in this description, all other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the scope of protection of this description. Unless otherwise specified, the reagent, method and equipment used in the present invention are conventional reagents, methods and equipment in the art, and the reagents and materials used in the following examples are all commercially available.

[0031] Polycarbonate diol PCDL2000 (CAS No.: 29862-10-0) was purchased from Hubei Dali Chemical Co., Ltd.;

[0032] Polytetrahydrofuran (CAS No.: 25190-06-1) was purchased from Jiangsu Bosite Chemical Technology Co., Ltd.;

[0033] Toluene-3,5-diisocyanate (CAS No.: 26471-62-5) was purchased from Jiangsu Bosite Chemical Technology Co., Ltd.;

[0034] Block copolymers of polystyrene-polyethylene-polypropylene-polystyrene were purchased from Changsha Jinguang Chemical Trading Co., Ltd.;

[0035] γ-Aminopropylmethyldiethoxysilane silane coupling agent KH-902 was purchased from Hubei Dali Chemical Co., Ltd.;

[0036] Nano-adhesive GY-2008 was purchased from Shenzhen Jingyi Chemical Co., Ltd.;

[0037] Terpene resin was purchased from Henan Jieshiman Petrochemical Co., Ltd.;

[0038] Silicon carbide (CAS No. 409-21-2) was purchased from Shandong West Asia Chemical Co., Ltd.;

[0039] Silicon dioxide (CAS No. 7631-86-9) was purchased from Nanjing Tianxing New Materials Co., Ltd.

[0040] Preparation Example 1

[0041] A polyoxime urethane comprises the following components in parts by weight: 7 parts of polytetrahydrofuran, 30 parts of diacetyl oxime, 12 parts of 1,4-butanediol, 85 parts of toluene-3,5-diisocyanate and 0.7 parts of dibutyltin dilaurate.

[0042] The preparation method of the polyoxime urethane comprises the following steps:

[0043] (1) adding polytetrahydrofuran, dimethylglyoxime and 1,4-butanediol into a reaction vessel containing acetone, and stirring and mixing them uniformly;

[0044] (2) Then, toluene-3,5-diisocyanate and dibutyltin dilaurate were added, stirred and mixed, poured into a polytetrafluoroethylene mold, and reacted in an oven at 50° C. for 3 hours, and dried to obtain a dynamically cross-linked polyoxime urethane.

[0045] The dynamically cross-linked polyoxime urethane is used in the following examples and comparative examples.

[0046] Preparation Example 2

[0047] A polycarbonate-based polyurethane, the preparation method comprising:

[0048] (1) Dry 80 parts of polycarbonate diol by weight to remove water, then add 20 parts of toluene-3,5-diisocyanate and 0.5 parts of dibutyltin dilaurate as a catalyst, set the speed to 150 r / min, and react at 75° C. for 3 hours to obtain a polyurethane prepolymer;

[0049] (2) Add 1.5 parts of chain extender 1,4-butanediol to the above polyurethane prepolymer, react for 10 minutes under mechanical stirring at 400 r / min, and place the reaction product in an oven at 110° C. for 8 hours to obtain a polycarbonate-based polyurethane.

[0050] The polycarbonate-based polyurethane was used in the following examples and comparative examples.

[0051] Example 1

[0052] A hot melt adhesive for automobile interior decoration, comprising the following raw materials in parts by weight:

[0053] 40 parts of polycarbonate-based polyurethane;

[0054] 30 parts of polyoxime urethane elastomer;

[0055] 7 parts of a block copolymer of polystyrene-polyethylene-polypropylene-polystyrene;

[0056] 7 parts of tackifier;

[0057] 1.5 parts of pentaerythritol tetravalerate;

[0058] 0.5 part of 2,2-methylene-bis(4-ethyl-6-tert-butylphenol);

[0059] The tackifier comprises tackifier A and nano-tackifier GY-2008 mixed in a mass ratio of 0.5:2, and fully stirred to obtain a uniform mixture. The tackifier A is obtained by mixing silicon carbide, silicon dioxide and γ-aminopropylmethyldiethoxysilane in a mass ratio of 2:2:0.5, and stirring for 3 hours.

[0060] The preparation method of the hot melt adhesive for automobile interior is as follows: weigh the raw materials of various components according to the proportion, add them into a twin-screw extruder, blend and extrude, and obtain the hot melt adhesive for automobile interior.

[0061] Example 2

[0062] A hot melt adhesive for automobile interior decoration, comprising the following raw materials in parts by weight:

[0063] 50 parts of polycarbonate-based polyurethane;

[0064] 20 parts of polyoxime urethane elastomer;

[0065] 7 parts of a block copolymer of polystyrene-polyethylene-polypropylene-polystyrene;

[0066] Thickener 9 parts;

[0067] 2 parts of pentaerythritol tetravalerate;

[0068] 0.5 part of 2,2-methylene-bis(4-ethyl-6-tert-butylphenol);

[0069] The tackifier comprises tackifier A and nano-tackifier GY-2008 mixed in a mass ratio of 1:2 and stirred thoroughly to obtain a uniform mixture. The tackifier A is obtained by mixing silicon carbide, silicon dioxide and γ-aminopropylmethyldiethoxysilane in a mass ratio of 2:1:0.5 and stirring for 3 hours.

[0070] The preparation method of the hot melt adhesive for automobile interior is as follows: weigh the raw materials of various components according to the proportion, add them into a twin-screw extruder, blend and extrude, and obtain the hot melt adhesive for automobile interior.

[0071] Example 3

[0072] A hot melt adhesive for automobile interior decoration, comprising the following raw materials in parts by weight:

[0073] 30 parts of polycarbonate-based polyurethane;

[0074] 30 parts of polyoxime urethane elastomer;

[0075] 5 parts of a block copolymer of polystyrene-polyethylene-polypropylene-polystyrene;

[0076] 5 parts of tackifier;

[0077] 1 part of pentaerythritol tetravalerate;

[0078] 0.5 part of 2,2-methylene-bis(4-ethyl-6-tert-butylphenol);

[0079] The tackifier comprises tackifier A and nano-tackifier GY-2008 mixed in a mass ratio of 1:1 and fully stirred to obtain a uniform mixture. The tackifier A is obtained by mixing silicon carbide, silicon dioxide and γ-aminopropylmethyldiethoxysilane in a mass ratio of 1:1:0.5 and stirring for 3 hours.

[0080] The preparation method of the hot melt adhesive for automobile interior is as follows: weigh the raw materials of various components according to the proportion, add them into a twin-screw extruder, blend and extrude, and obtain the hot melt adhesive for automobile interior.

[0081] Comparative Example 1

[0082] Compared with Example 1, the difference is that the polyoxime urethane elastomer is not included, and the other aspects are the same.

[0083] The preparation method of the hot melt adhesive provided in this comparative example is the same as that in Example 1.

[0084] Comparative Example 2

[0085] Compared with Example 1, the difference is that the polyoxime urethane elastomer is replaced by polyurethane in equal parts by weight, and the other parts are the same.

[0086] The preparation method of the polyurethane is as follows: 50 parts of 1,4-butanediol are added into a reaction container filled with acetone, and the mixture is stirred and mixed evenly, and then 80 parts of toluene-3,5-diisocyanate and 1 part of dibutyltin dilaurate are added, and the mixture is stirred and mixed, and then poured into a polytetrafluoroethylene mold, and the mixture is reacted in an oven at 50° C. for 3 hours, and dried to obtain the polyurethane.

[0087] The preparation method of the hot melt adhesive provided in this comparative example is the same as that in Example 1.

[0088] Comparative Example 3

[0089] Compared with Example 1, the difference is that the block copolymer of polystyrene-polyethylene-polypropylene-polystyrene is not included, and the other contents are the same.

[0090] The preparation method of the hot melt adhesive provided in this comparative example is the same as that in Example 1.

[0091] Comparative Example 4

[0092] Compared with Example 1, the difference is that no tackifier is included, and the other aspects are the same.

[0093] The preparation method of the hot melt adhesive provided in this comparative example is the same as that in Example 1.

[0094] Comparative Example 5

[0095] Compared with Example 1, the difference is that the tackifier is nano tackifier GY-2008, and the others are the same.

[0096] The preparation method of the hot melt adhesive provided in this comparative example is the same as that in Example 1.

[0097] Comparative Example 6

[0098] Compared with Example 1, the difference is that the tackifier is tackifier A, and the others are the same.

[0099] The tackifier A is obtained by mixing silicon carbide, silicon dioxide and a coupling agent in a mass ratio of (1-2):(1-2):(0.1-0.5), and stirring the mixture for 3 hours.

[0100] The preparation method of the hot melt adhesive provided in this comparative example is the same as that in Example 1.

[0101] Comparative Example 7

[0102] Compared with Example 1, the difference is that the tackifier is terpene resin, and the other parts are the same.

[0103] The preparation method of the hot melt adhesive provided in this comparative example is the same as that in Example 1.

[0104] Performance Test:

[0105] 1. Adhesion ability test

[0106] The initial bonding strength of the hot melt adhesive (the sample substrate is ABS, and the tensile shear strength is tested after the sample is placed for 10 minutes and 30 minutes respectively) and the final bonding strength (the sample substrate is ABS, and the tensile shear strength is tested after the sample is wet-cured for 7 days at 25℃ / 50%RH) are tested according to GB / T 7124-2008.

[0107] The test results are shown in Table 1.

[0108] Table 1 Adhesion performance test results

[0109]

[0110] It can be seen from Table 1 that the hot melt adhesives provided by Examples 1-3 of the present invention have fast curing speed and strong bonding strength.

[0111] Compared with Example 1, Comparative Example 1 does not contain polyoxime urethane elastomer, and the initial bonding strength decreases, and the final bonding strength decreases.

[0112] In Comparative Example 2, compared with Example 1, the polyoxime urethane elastomer was replaced with an equal weight portion of polyurethane, and the initial bonding strength decreased significantly, and the final bonding strength decreased slightly.

[0113] Compared with Example 1, Comparative Example 3 does not contain a block copolymer of polystyrene-polyethylene-polypropylene-polystyrene, and the initial bonding strength decreases to a certain extent, and the final bonding strength decreases.

[0114] Compared with Example 1, Comparative Example 4 does not contain a tackifier, and the final bonding strength is significantly reduced.

[0115] In Comparative Example 5, compared with Example 1, the tackifier is nano tackifier GY-2008, the initial bonding strength decreases slightly, and the final bonding strength decreases significantly.

[0116] In Comparative Example 6, compared with Example 1, the tackifier is tackifier A, the initial bonding strength decreases slightly, and the final bonding strength decreases significantly.

[0117] Compared with Example 1, in Comparative Example 7, the tackifier is terpene resin, the initial bonding strength decreases to a certain extent, and the final bonding strength decreases significantly.

[0118] 2. Durability test

[0119] (1) Self-healing performance test: After curing (curing for 48 h at 25°C and 60% RH), scratches were made on the surface of the hot melt adhesive using a steel wire brush, and the time it took for the scratches to disappear was measured.

[0120] (2) Mechanical property testing after repair: The polyurethane hot melt adhesive sample of Example 1 was cut after curing (curing for 48 h at 25°C and 60% RH) and then repaired at 40°C. The tensile strength of the original (sample before cutting) and the repaired sample was tested with reference to the method specified in GB / T528-2009.

[0121] The test results are shown in Table 2.

[0122] Table 2 Repair ability test results

[0123]

[0124] It can be seen from Table 2 that the hot melt adhesives of Examples 1-3 of the present invention have fast self-repairing speed, excellent tensile strength, and good tensile strength performance after repair. The hot melt adhesives of Comparative Examples 1-2 have average self-repairing ability and require a long repair time; the hot melt adhesives of Comparative Examples 3-6 have good self-repairing ability, but the tensile strength is worse than that of Example 1; the hot melt adhesive of Comparative Example 7 has average self-repairing performance, which is worse than that of Comparative Examples 3-6, and average tensile strength.

[0125] In summary, the hot melt adhesive provided by the present invention has a fast curing speed, strong bonding ability, and excellent mechanical properties. It can quickly repair scratches and damages, thereby improving the reliability and durability of the material.

[0126] Although the embodiments of the present description have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present description, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hot melt adhesive for automobile interior, characterized in that: The invention comprises the following raw materials in parts by weight: 30-50 parts of polycarbonate-based polyurethane; 15-30 parts of polyoxime urethane; 5-15 parts of block copolymer of polystyrene-polyethylene-polypropylene-polystyrene; 1-9 parts of composite tackifier; 0.5-5 parts of plasticizer; 0.1-3 parts of anti-aging agent; the composite tackifier comprises tackifier A and tackifier B, which are compounded in a mass ratio of (0.5-1):(1-2); the tackifier A is obtained by mixed reaction of silicon carbide, silicon dioxide and coupling agent, and the tackifier B is nano tackifier GY-2008; the mass ratio of silicon carbide, silicon dioxide and coupling agent in the tackifier A is (1-2):(1-2):(0.1-0.5); The oxime urethane comprises the following components in parts by weight, and the components are reacted according to a ratio: 6-8 parts of polytetrahydrofuran, 20-40 parts of dimethylglyoxime, 10-20 parts of 1,4-butanediol, 70-110 parts of toluene-3,5-diisocyanate and 0.5-1.5 parts of dibutyltin dilaurate. The preparation method of the polyoxime urethane comprises the following steps: (1) adding polytetrahydrofuran, dimethylglyoxime and 1,4-butanediol into a reaction container filled with acetone, and stirring and mixing them uniformly; (2) then adding toluene-3,5-diisocyanate and dibutyltin dilaurate, mixing them uniformly, and pouring them into a polytetrafluoroethylene mold, reacting them in an oven at 40-60°C for 1-6 hours, and drying to obtain the polyoxime urethane.

2. The hot melt adhesive for automotive interior according to claim 1, characterized in that: The coupling agent is an aminosilane coupling agent.

3. The hot melt adhesive for automotive interior according to claim 2, characterized in that: The aminosilane coupling agent is selected from at least one of γ-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane.

4. The hot melt adhesive for automotive interior according to claim 1, characterized in that: The antioxidant is 2,2-methylene-bis(4-ethyl-6-tert-butylphenol).

5. The hot melt adhesive for automotive interior according to claim 1, characterized in that: The plasticizer is pentaerythritol tetravalerate.

6. The hot melt adhesive for automotive interior according to claim 1, characterized in that: The polycarbonate-based polyurethane is obtained by prepolymerizing polycarbonate diol and isocyanate and then undergoing a small molecule chain extension reaction.

7. The method for preparing the hot melt adhesive for automobile interior decoration according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: weighing raw materials of various components according to a proportion, adding the raw materials into a twin-screw extruder, blending and extruding the raw materials, and obtaining hot melt adhesive for automobile interior decoration.

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