Modified chlorinated polypropylene resin, preparation method thereof and application of modified chlorinated polypropylene resin in preparation of water-based prime coat of bumper

Abstract

The invention discloses modified chlorinated polypropylene resin, a preparation method thereof and application of the modified chlorinated polypropylene resin in preparation of a water-based prime coat of a bumper, and belongs to the technical field of prime coats. The water-based prime coat for the bumper is high in hardness, the surface is not sticky, and low-temperature activation and flame-free treatment can be achieved. The bumper prime coat resin prepared by the invention comprises three components: the first component is carbon dioxide-based polyol, and carbonic ester and ether bond structures in the structure can improve the hydrolysis resistance of a water-based prime coat and improve the humidity and heat resistance of the prime coat resin; the second component is a rigid benzene ring structure of sodium p-styrenesulfonate and styrene in the structural formula, so that the hardness of the water-based prime coat resin is improved, and the problem that the surface of a paint film is sticky is solved; and the third component sodium p-styrenesulfonate group ensures the water dispersibility of the prime coat resin.

Description

Technical Field

[0001] The invention belongs to the technical field of primers, and in particular relates to a modified chlorinated polypropylene resin and a preparation method thereof, and application of the modified chlorinated polypropylene resin in preparing a water-based primer for a bumper. Background Art

[0002] Polypropylene material has the advantages of light weight, good toughness, low price and excellent chemical resistance, and has been widely used in the field of automobile bumpers. However, polypropylene is a non-polar material with low surface energy, which makes its surface difficult to wet. Therefore, before the bumper material is painted, it needs to be flame treated first, and then a layer of 15-20% chlorinated polypropylene primer solution is applied to enhance the surface adhesion of the bumper, and at the same time, it can enhance the interlayer adhesion with other coatings. In recent years, with the introduction of national environmental protection policies, water-based primers for bumpers have become a development trend in this field. However, water-based chlorinated polypropylene resin, as the main resin of water-based primer resin, needs to be grafted and modified during the preparation process, resulting in the problem of stickiness of the obtained water-based primer resin at room temperature, and the hardness of the paint film is particularly low, which cannot meet the requirements of automotive-grade primer resins. In addition, compared with solvent-based primers, water-based primer resins require high-temperature activation above 90°C, which not only consumes energy, but also causes the risk of bumper deformation. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] In view of the problems existing in the field, the purpose of the present invention is to provide a high-hardness, non-sticky surface, low-temperature activated and flame-treatment-free bumper water-based primer and its preparation method. The bumper primer resin structure provided by the present invention includes three components: the first component is a carbon dioxide-based polyol, and the carbonate and ether bond structure in the structure can improve the hydrolysis resistance of the water-based primer and the moisture and heat resistance of the primer resin; the second component is the sodium styrene sulfonate and the rigid benzene ring structure of styrene in the structural formula, which improves the hardness of the water-based primer resin and the problem of stickiness on the paint film surface; the third component is the sodium styrene sulfonate group, which ensures the water dispersibility of the primer resin.

[0005] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a modified chlorinated polypropylene resin. The modified chlorinated polypropylene resin has a main chain structure of chlorinated polypropylene, and a rigid structure styrene unit, a sodium styrene sulfonate unit and a carbon dioxide-based polyol structural unit are grafted onto its side chains respectively;

[0007] The styrene units and sodium styrene sulfonate units are grafted into the main chain structure through free radical polymerization, and the carbon dioxide-based polyol units are connected to the main chain structure through a polyurethane reaction;

[0008] The mass ratio of the chlorinated polypropylene to styrene, sodium styrene sulfonate and carbon dioxide-based polyol is 160-350: 10.5-14.8: 12.5-20.8: 420-510;

[0009] The weight average molecular weight Mw of the chlorinated polypropylene is 100,000 to 250,000, wherein the mass content of chlorine is 10 to 30%.

[0010] The modified chlorinated polypropylene resin also has a structure as shown in general formula (I):

[0011]

[0012] Among them, R is selected from One of them.

[0013] Another object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a modified chlorinated polypropylene resin.

[0014] In order to solve the above technical problems, the present invention provides the following technical solutions, including:

[0015] 160-350 parts of chlorinated polypropylene and 200-400 parts of toluene are mixed and heated until the chlorinated polypropylene is completely dissolved to obtain a chlorinated polypropylene liquid;

[0016] 12.5-20.8 parts of sodium styrene sulfonate, 10.5-14.8 parts of styrene, 20.6-30.5 parts of the intermediate, and 180-300 parts of toluene are mixed until completely dissolved to obtain a grafting solution;

[0017] 2.1-3.6 parts of initiator and 20-45 parts of toluene are mixed until completely dissolved to obtain an initiator solution;

[0018] Under the protection of nitrogen atmosphere, the chlorinated polypropylene liquid and the grafting liquid are mixed, the temperature is raised to 60-80°C, and the initiator solution is added dropwise, the reaction is continued for 1-3 hours, and the solvent is removed under reduced pressure to obtain a grafted chlorinated polypropylene intermediate;

[0019] 50.8-81.6 parts of grafted chlorinated polypropylene intermediate, 18.5-23.7 parts of diisocyanate, 420-510 parts of carbon dioxide-based polyol and 3.5-4.2 parts of trimethylolpropane are uniformly mixed and reacted at 70-85°C for 1-2 hours, and then 0.3-0.8 parts of antioxidant, 2.4-4.1 parts of butanediol and 0.3-0.8 parts of catalyst are added, twin-screw melt extrusion is carried out, and underwater pelletizing is carried out to obtain modified chlorinated polypropylene resin.

[0020] As a preferred embodiment of the method for preparing the modified chlorinated polypropylene resin of the present invention, the method for preparing the intermediate comprises:

[0021] 100-110 parts of maleic anhydride and 140-150 parts of 1-naphthylamine are mixed and added with xylene, 0.1-0.5 parts of hydroquinone and 0.5-1.0 parts of p-toluenesulfonic acid, and reacted at 120-150°C for 4-8 hours, then 30% sodium carbonate solution is added, and the mixture is allowed to stand for stratification, and the xylene layer is washed and dried, and the xylene is removed under reduced pressure to obtain an intermediate precursor;

[0022] The intermediate precursor is dissolved in isopropanol, and sodium borohydride is added in five batches. After all the sodium borohydride is added, the temperature is raised to 55-75°C, and the reaction is carried out for 3-5 hours. The temperature is then lowered to room temperature, deionized water is added, and the mixture is stirred for 15 minutes. After the pH value is adjusted to neutral, the isopropanol and deionized water are evaporated under reduced pressure, deionized water and methylcyclohexane are added, and the mixture is stirred at room temperature for 20 minutes. The mixture is allowed to stand and the layers are separated. The methylcyclohexane organic layer is retained, and the mixture is washed, dried, and the solvent is removed to obtain the intermediate.

[0023] As a preferred embodiment of the method for preparing the modified chlorinated polypropylene resin of the present invention, the method for preparing the intermediate comprises:

[0024] 107.9 parts of maleic anhydride and 145.8 parts of 1-naphthylamine were mixed and added with xylene, 0.35 parts of hydroquinone and 0.8 parts of p-toluenesulfonic acid, and reacted at 130°C for 6 hours, then 30% sodium carbonate solution was added, and the mixture was allowed to stand for stratification. The xylene layer was washed and dried, and the xylene was removed under reduced pressure to obtain an intermediate precursor;

[0025] The intermediate precursor was dissolved in isopropanol, and sodium borohydride was added in five batches. After all the sodium borohydride was added, the temperature was raised to 65°C. After reacting for 4.5 hours, the temperature was lowered to room temperature, deionized water was added, and the mixture was stirred for 15 minutes. After the pH value was adjusted to neutral, the isopropanol and deionized water were evaporated under reduced pressure, deionized water and methylcyclohexane were added, and the mixture was stirred at room temperature for 20 minutes. The mixture was allowed to stand and the methylcyclohexane organic layer was retained. The mixture was washed, dried, and the solvent was removed to obtain the intermediate.

[0026] As a preferred embodiment of the method for preparing the modified chlorinated polypropylene resin of the present invention, the dropping rate of the initiator is 1.5-4.0 ml / min.

[0027] As a preferred embodiment of the preparation method of the modified chlorinated polypropylene resin of the present invention, wherein: the weight average molecular weight Mw of the chlorinated polypropylene is 100,000 to 250,000, and the mass content of chlorine is 10 to 30%;

[0028] The initiator includes one or more of benzoyl peroxide, dicumyl peroxide, dilauroyl peroxide, 1,1-di(tert-butylperoxy)3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butyl peroxyacetate, tert-amyl peroxy-2-ethylhexanoate, and dilauroyl peroxide.

[0029] As a preferred embodiment of the preparation method of the modified chlorinated polypropylene resin of the present invention, the diisocyanate includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and xylylene diisocyanate.

[0030] As a preferred embodiment of the preparation method of the modified chlorinated polypropylene resin of the present invention, wherein: the number average molecular weight of the carbon dioxide-based polyol is 3300-6000, and the unit content is 30.6-54.8%;

[0031] The antioxidant includes one or more of hindered phenols and phosphite antioxidants, including one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 1790, and antioxidant 168;

[0032] The catalyst is an organic metal catalyst, including one or more of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate.

[0033] As a preferred embodiment of the preparation method of the modified chlorinated polypropylene resin of the present invention, the twin-screw melt extrusion is performed, wherein the process temperature of each section of the screw is 120-130°C, 145-155°C, 160-170°C, 170-180°C, 170-180°C, 170-180°C, 160-170°C, 160-170°C, 155-165°C, 155-165°C, the die temperature is 150-160°C, the rotation speed is 200-300rpm, and the total time is 2-4min.

[0034] As a preferred scheme of the preparation method of the modified chlorinated polypropylene resin of the present invention, wherein: the twin-screw melt extrusion, wherein the process temperature of each section of the screw is 130°C, 150°C, 165°C, 175°C, 175°C, 175°C, 165°C, 165°C, 160°C, 160°C, the die head temperature is 155°C, the rotation speed is 275rpm, and the total residence time is 3min.

[0035] Another object of the present invention is to overcome the deficiencies in the prior art and provide a modified chlorinated polypropylene resin for use in preparing a water-based primer for a bumper.

[0036] In order to solve the above technical problems, the present invention provides the following technical solution, wherein the bumper water-based primer comprises one of a water-based primer paint and a water-based primer emulsion.

[0037] Another object of the present invention is to overcome the deficiencies in the prior art and provide an aqueous primer emulsion, the preparation method of which comprises:

[0038] 15-25 parts of modified chlorinated polypropylene resin, 55-65 parts of deionized water and 0.1-0.5 parts of sodium dodecyl sulfate are uniformly mixed, and emulsified at 80-90° C. with stirring; after the emulsification is completed, the mixture is cooled to room temperature to obtain a bumper water-based primer resin emulsion;

[0039] The stirring speed is 1100-1300 rpm, and the stirring time is 20-40 min.

[0040] As a preferred embodiment of the method for preparing the aqueous primer emulsion of the present invention, the method comprises:

[0041] 20 parts of water-based primer resin, 60 parts of deionized water and 0.3 parts of sodium lauryl sulfate were mixed evenly, and emulsified at 85° C. under stirring; after the emulsification, the mixture was cooled to room temperature to obtain a bumper water-based primer resin emulsion;

[0042] Among them, the stirring speed is 1100-1300 rpm, and the stirring time is 30 minutes.

[0043] Another object of the present invention is to overcome the deficiencies in the prior art and provide a water-based primer, the preparation method of which comprises:

[0044] Mix 260-400 parts of titanium dioxide, 5-12 parts of carbon black, 2-8 parts of water-based wetting and dispersing agent, and 4-7 parts of water-based defoaming agent, and grind them for 2-4 hours. When the fineness reaches 8 μm, add 1680-2850 parts of water-based primer resin, 160-220 parts of film-forming aid, 1.5-4 parts of water-based wetting and leveling agent, 3-5 parts of white carbon black, and 28-45 parts of water-based curing agent, and disperse at high speed to obtain a water-based base paint for bumpers.

[0045] Wherein, the stirring rate of the high-speed dispersion is 300-500 rpm, and the stirring time is 5-8 min.

[0046] As a preferred embodiment of the water-based primer of the present invention, the film-forming aid is one or more of dodecyl alcohol ester, diethylene glycol butyl ether, dipropylene glycol monobutyl ether, dipropylene glycol methyl ether, dipropylene glycol monopropyl ether, and tripropylene glycol monobutyl ether.

[0047] The aqueous wetting and dispersing agent is one or more of BYK-180, BYK-190, BYK-191, BYK-192, BYK-194, BYK-199 and BYK-2015.

[0048] The aqueous defoamer is one or more of BYK-022, BYK-024, BYK-028, BYK-093, BYK-1786, TEGO FOAMEX822, TEGO AIREX 901W and TEGO AIREX 902W.

[0049] The aqueous wetting and leveling agent is one or more of BYK-346, BYK-381, BYK-3456, BYK-3760 or DAPROW-77.

[0050] The water-based curing agent is preferably one or more of Bayhydur 3100, Bayhydur 2451, Bayhydur XP 2655 and Desmodur N 3800.

[0051] The carbon black is selected from Cabot carbon black, BP2000, REGAL 250R, and REGAL 400R.

[0052] The white carbon black is preferably one or more of R972, R974, R816, R805 and R812 manufactured by Evonik.

[0053] Beneficial effects of the present invention:

[0054] The present invention prepares a flame-free, high-hardness water-based bottom coating resin for bumpers, the hardness of which reaches 1H to 2H, which is much higher than that of a water-based allyl chloride emulsion system. Moreover, flame-free, construction is more convenient.

[0055] The bumper primer resin prepared by the present invention comprises three components: the first component is a carbon dioxide-based polyol, the carbonate and ether bond structure in the structure can improve the hydrolysis resistance of the water-based primer and the moisture and heat resistance of the primer resin; the second component is sodium styrene sulfonate in the structural formula and the rigid benzene ring structure of styrene, which improve the hardness of the water-based primer resin and solve the problem of stickiness on the paint film surface; the third component is the sodium styrene sulfonate group, which ensures the water dispersibility of the primer resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0057] Figure 1 This is the ATR spectrum of the modified chlorinated polypropylene resin prepared in Example 1 of the present invention.

[0058] Figure 2 This is a SEM image of the modified chlorinated polypropylene resin prepared in Example 1 of the present invention.

[0059] Figure 3 This is the ATR spectrum of the modified chlorinated polypropylene resin prepared in Example 2 of the present invention.

[0060] Figure 4 This is a SEM image of the modified chlorinated polypropylene resin prepared in Example 2 of the present invention.

[0061] Figure 5 This is a SEM image of the resin prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0062] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0063] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0064] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0065] The raw materials used in the present invention are all commercially available unless otherwise specified.

[0066] The carbon dioxide-based polyol was prepared according to the method reported in invention patent 201110231493.6.

[0067] Preparation method of the intermediate: 107.9g of maleic anhydride and 145.8g of 1-naphthylamine are put into a reaction bottle, xylene, 0.35g of hydroquinone, 0.8g of p-toluenesulfonic acid are added, the temperature is controlled at 130°C, the reaction is carried out for 6h, and then 450ml of 30% sodium carbonate solution is added, and the layers are separated. The xylene layer is separated. Then the xylene layer is washed 3 times with 300ml of deionized water, and the xylene organic layer is dried with anhydrous magnesium sulfate. After drying, the xylene is removed under reduced pressure to obtain the intermediate precursor. The intermediate precursor is dissolved in 450ml of isopropanol, and sodium borohydride is added in five batches at room temperature. After all are added, the temperature is raised to 65°C, and after reacting for 4.5h, the temperature is lowered to room temperature, 600ml of deionized water is added, and the mixture is stirred for 15min. The pH value is adjusted to neutral with 30% sulfuric acid, and the isopropanol and deionized water are evaporated under reduced pressure. Add 500 ml of deionized water and 700 ml of methylcyclohexane, stir at room temperature for 20 min, let stand and separate the layers, remove the water layer, retain the methylcyclohexane organic layer, wash the organic layer with 650 ml of deionized water 5 times, dry the obtained organic layer with anhydrous magnesium sulfate, remove the solvent after drying, and obtain the intermediate.

[0068] The performance of the material prepared in the embodiment of the present invention was tested as follows:

[0069] The dust on the surface of the bumper composite polypropylene composite material is wiped clean with a dust-free cloth, and then the water-based primer is sprayed on the surface by air spraying at a humidity of 65% and a temperature of 25°C. It is activated in a 60°C oven for 5 minutes, and the dry film thickness is 10-12 microns. After seven days, the paint film related performance tests are carried out.

[0070] 1. Particle size test: The water-based primer resin was diluted in a Malvern cuvette (DTS0012), and then tested by a Brookhaven ZetaPlus analyzer dynamic light scattering (DLS) instrument at a test temperature of 25°C.

[0071] 2. ATR (total reflection infrared) performance test: The prepared resin was placed in a polytetrafluoroethylene tray, placed at room temperature for 48 hours, dried, and vacuum dried at 40°C for 72 hours. The ATR performance test was performed using a German Bruker INVENIO-R Fourier transform infrared spectrometer. The parameters were diamond reflection crystal and the scanning range was 4000-400 cm -1 ; Resolution: 4cm -1 , scan times: 128 times.

[0072] 3. SEM (Scanning Electron Microscope) Test: The resin sample was placed in liquid nitrogen, taken out, broken, and gold-sprayed on the cross section. The SEM performance test was performed on an XL-30 field emission scanning electron microscope.

[0073] 4. Emulsion stability test: Centrifuge the water-based primer resin at 5000 rpm for 30 minutes and observe whether there is precipitation at the bottom.

[0074] 5. Adhesion (cross-cut method) test: Test in accordance with GB / T 13217.7-2009.

[0075] 6. Hardness (pencil hardness) test: Test in accordance with GB / T 6739-2022 method.

[0076] 7. Steam injection and climate change are tested according to TL211 standard method.

[0077] Example 1

[0078] This embodiment provides a method for preparing a modified chlorinated polypropylene resin, specifically:

[0079] 1) Preparation of chlorinated polypropylene solution: 160 parts of chlorinated polypropylene (Mw = 100,000, chlorine content = 10%) were added to 200 份 The mixture was added toluene and heated to 65°C to completely dissolve the chlorinated polypropylene to obtain a chlorinated polypropylene liquid.

[0080] 2) Preparation of grafting solution: 12.5 parts of sodium styrene sulfonate, 10.5 parts of styrene and 20.6 parts of the intermediate were added to 180 parts of toluene and stirred at room temperature for 30 minutes to obtain a grafting solution.

[0081] 3) Preparation of an initiator solution: Dissolve 2.1 parts of benzoyl peroxide in 20 parts of toluene until the mixture is completely dissolved to obtain an initiator solution having a mass fraction of 10.5%.

[0082] 4) Under nitrogen protection, the chlorinated polypropylene liquid and the grafting liquid were mixed, the reaction temperature was raised to 60°C, and the initiator solution was added dropwise at a rate of 1.5 ml / min. After all the initiator solution was added, the reaction was continued for 3 hours, and the solvent was removed under reduced pressure to obtain a grafted chlorinated polypropylene intermediate;

[0083] 5) 50.8 parts of grafted chlorinated polypropylene intermediate, 18.5 parts of toluene diisocyanate, 420 parts of carbon dioxide-based polyol (Example 15 in invention patent 201110231493.6, Mn=3300Da, Cu%=30.6%) and 3.5 parts of trimethylolpropane were mixed and reacted at 70°C for 2h. Then the material was added to the twin screw, 0.3 parts of antioxidant 1010, 2.4 parts of butanediol and 0.5 parts of dibutyltin dilaurate were added, the screw process temperature was 130°C, 150°C, 165°C, 175°C, 175°C, 165°C, 165°C, 160°C, 160°C, the die temperature was 155°C, the rotation speed was 275rpm, the total residence time was 3min, and finally, underwater pelletizing was performed to obtain modified chlorinated polypropylene resin.

[0084] The main chain structure of the modified chlorinated polypropylene resin of this embodiment is chlorinated polypropylene, and rigid structure styrene units, sodium styrene sulfonate units and carbon dioxide-based polyol structural units are grafted on its side chains respectively; wherein the styrene units and sodium styrene sulfonate units are grafted into the main chain structure by free radical polymerization, and the carbon dioxide-based polyol units are connected to the main chain structure by polyurethane reaction.

[0085] Figure 1 ATR spectrum of the modified chlorinated polypropylene resin prepared in this example: 553.5 cm -1 , 702.1cm -1 , 831.2cm -1 , 946.9cm -1 , 1110.9cm -1 , 1247.8cm -1 , 1377.1cm -1 , 1452.3cm -1 , 1512.1cm -1 , 1612.4cm -1 , 1728.1cm -1 , 2873.7cm -1 , 2921.9cm -1 , 2952.8cm -1 , 3205.5cm -1 , 3352.1cm -1 , 3442.7cm -1 . 2400cm in the spectrum -1~1900cm -1 These are the mixed peaks of diamond and carbon dioxide in the atmosphere.

[0086] The peak position of the infrared spectrum shows that the target resin product is successfully obtained.

[0087] Example 2

[0088] 1) 350 parts of chlorinated polypropylene (Mw: 250,000, chlorine content: 30% by mass) were added to 400 parts of toluene, and the temperature was raised to 90° C. to completely dissolve the chlorinated polypropylene to form a chlorinated polypropylene liquid;

[0089] 2) adding 20.8 parts of sodium styrene sulfonate, 14.8 parts of styrene, and 30.5 parts of the intermediate to 300 parts of toluene, stirring at room temperature for 30 minutes, to obtain a grafting solution;

[0090] 3) dissolving 3.6 parts of dicumyl peroxide in 45 parts of toluene until completely dissolved to obtain an initiator solution;

[0091] 4) Under nitrogen protection, the chlorinated polypropylene liquid and the grafting liquid were mixed, the reaction temperature was raised to 80°C, and the initiator solution was added dropwise at a rate of 4 ml / min. After all the initiator solution was added, the reaction was continued for 1 hour, and the solvent was removed under reduced pressure to obtain a grafted chlorinated polypropylene intermediate;

[0092] 5) 81.6 parts of grafted chlorinated polypropylene intermediate, 23.7 parts of diphenylmethane diisocyanate, 510 parts of carbon dioxide-based polyol (Example 8 in invention patent 201110231493.6, Mn=6000Da, Cu%=34.3%) and 4.2 parts of trimethylolpropane were mixed and reacted at 85°C for 1h. Then the material was added to the twin screw, 0.8 parts of antioxidant 1076, 4.1 parts of butanediol and 0.5 parts of stannous octoate were added, the screw process temperature was 130°C, 150°C, 165°C, 175°C, 175°C, 165°C, 165°C, 160°C, 160°C, the die temperature was 155°C, the rotation speed was 275rpm, the total residence time was 3min, and finally, underwater pelletizing was performed to obtain modified chlorinated polypropylene resin.

[0093] Figure 3 ATR spectrum of the modified chlorinated polypropylene resin prepared in this example: 559.3 cm -1 , 707.8cm -1 , 827.4cm -1 , 947.1cm -1 , 1136.0cm -1 , 1245.9cm -1 , 1374.6cm -1 , 1453.8cm -1, 1514.0cm -1 , 1606.4cm -1 , 1728.5cm -1 , 2871.8cm -1 , 2922.3cm -1 , 2950.9cm -1 , 3188.8cm -1 , 3441.5cm -1 . 2400cm in the spectrum -1 ~1900cm -1 These are the mixed peaks of diamond and carbon dioxide in the atmosphere.

[0094] The peak position of the infrared spectrum shows that the target resin product is successfully obtained.

[0095] Example 3

[0096] 1) adding 240 parts of chlorinated polypropylene (Mw: 150,000, chlorine content: 15% by mass) into 300 parts of toluene, heating to 70°C to completely dissolve the chlorinated polypropylene to form a chlorinated polypropylene liquid;

[0097] 2) adding 14.8 parts of sodium styrene sulfonate, 11.6 parts of styrene, and 24.5 parts of the intermediate to 210 g of toluene, stirring at room temperature for 30 min to obtain a grafting solution;

[0098] 3) dissolving 2.6 g of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane in 30 g of toluene until it is completely dissolved to obtain an initiator solution;

[0099] 4) Under nitrogen protection, the chlorinated polypropylene liquid and the grafting liquid were mixed, the reaction temperature was raised to 70°C, and the initiator solution was added dropwise at a rate of 2.5 ml / min. After all the initiator solution was added, the reaction was continued for 2 hours, and the solvent was removed under reduced pressure to obtain a grafted chlorinated polypropylene intermediate;

[0100] 5) 61.2g grafted chlorinated polypropylene intermediate, 21.5g isophorone diisocyanate, 480g carbon dioxide-based polyol (Example 12 in invention patent 201110231493.6, Mn=5800Da, Cu%=35.2%) and 3.7g trimethylolpropane were mixed and reacted at 75°C for 1.5h. Then the material was added to the twin screw, 0.5g antioxidant 1098, 2.9g butanediol and 0.5g dibutyltin diacetate were added, the screw process temperature was 130°C, 150°C, 165°C, 175°C, 175°C, 165°C, 165°C, 160°C, 160°C, the die temperature was 155°C, the rotation speed was 275rpm, the total residence time was 3min, and finally, underwater pelletizing was performed to obtain modified chlorinated polypropylene resin.

[0101] ATR spectrum of the modified chlorinated polypropylene resin prepared in this example: 554.2 cm -1 , 703.5cm -1 , 824.9cm -1 , 948.6cm -1 , 1122.7cm -1 , 1240.8cm -1 , 1370.6cm -1 , 1455.3cm -1 , 1512.8cm -1 , 1610.3cm -1 , 1730.2cm -1 , 2873.5cm -1 , 2920.2cm -1 , 2953.4cm -1 , 3186.2cm -1 , 3440.9cm -1 . 2400cm -1 ~1900cm -1 These are the mixed peaks of diamond and carbon dioxide in the atmosphere.

[0102] Example 4

[0103] 1) 310 g of chlorinated polypropylene (Mw=200,000, chlorine content of 22%) was added to 350 g of toluene, and the temperature was raised to 80° C. to completely dissolve the chlorinated polypropylene to form a chlorinated polypropylene liquid;

[0104] 2) adding 18.5 g of sodium styrene sulfonate, 13.2 g of styrene and 28.5 g of the intermediate to 280 g of toluene and stirring at room temperature for 30 min to obtain a grafting solution;

[0105] 3) dissolving 2.8 g of dilauroyl peroxide in 35 g of toluene until it is completely dissolved to obtain an initiator solution;

[0106] 4) Under nitrogen protection, the chlorinated polypropylene liquid and the grafting liquid were mixed, the reaction temperature was raised to 75°C, and the initiator solution was added dropwise at a rate of 3.5 ml / min. After all the initiator solution was added, the reaction was continued for 2 hours, and the solvent was removed under reduced pressure to obtain a grafted chlorinated polypropylene intermediate;

[0107] 5) 66.5g of grafted chlorinated polypropylene intermediate, 19.6g of dicyclohexylmethane diisocyanate, 500g of carbon dioxide-based polyol (Example 17 in invention patent 201110231493.6, Mn=3500Da, Cu%=54.8%) and 3.8g of trimethylolpropane were mixed and reacted at 75°C for 1.5h. Then the material was added to the twin screw, 0.4g of antioxidant 1790, 3.6g of butanediol and 0.8g of dibutyltin dilaurate were added, the screw process temperature was 130°C, 150°C, 165°C, 175°C, 175°C, 165°C, 165°C, 160°C, 160°C, the die temperature was 155°C, the rotation speed was 275rpm, the total residence time was 3min, and finally, underwater pelletizing was performed to obtain modified chlorinated polypropylene resin.

[0108] ATR spectrum of the modified chlorinated polypropylene resin prepared in this example: 561.3 cm -1 , 703.9cm -1 , 825.2cm -1 , 951.8cm -1 , 1132.5cm -1 , 1247.2cm -1 , 1371.6cm -1 , 1458.2cm -1 , 1510.6cm -1 , 1602.9cm -1 , 1730.2cm -1 , 2868.5cm -1 , 2918.4cm -1 , 2948.1cm -1 , 3180.7cm -1 , 3445.9cm -1 . 2400cm -1 ~1900cm -1 These are the mixed peaks of diamond and carbon dioxide in the atmosphere.

[0109] Example 5

[0110] 1) 320 g of chlorinated polypropylene (Mw=150,000, chlorine content of 17%) was added to 400 g of toluene, and the temperature was raised to 85° C. to completely dissolve the chlorinated polypropylene to form a chlorinated polypropylene liquid;

[0111] 2) adding 17.6 g of sodium styrene sulfonate, 13.5 g of styrene and 26.5 g of the intermediate to 260 parts of toluene and stirring at room temperature for 30 min to obtain a grafting solution;

[0112] 3) dissolving 3.4 parts of tert-amyl peroxy 2-ethylhexanoate in 30 parts of toluene until completely dissolved to obtain an initiator solution;

[0113] 4) Under nitrogen protection, the chlorinated polypropylene liquid and the grafting liquid were mixed, the reaction temperature was raised to 70°C, and the initiator solution was added dropwise at a rate of 3 ml / min. After all the initiator solution was added, the reaction was continued for 2 hours, and the solvent was removed under reduced pressure to obtain a grafted chlorinated polypropylene intermediate;

[0114] 5) 71.5 parts of grafted chlorinated polypropylene intermediate, 22.5 parts of diisocyanate, 480 parts of carbon dioxide-based polyol (invention patent 201110231493.6, Example 16, Mn = 3300Da, Cu% = 39.3%) and 3.9 parts of trimethylolpropane were mixed and reacted at 80°C for 1.5h. Then the material was added to the twin screw, 0.7 parts of antioxidant 168, 3.7 parts of butanediol and 0.3 parts of stannous octoate were added, the screw process temperature was 130°C, 150°C, 165°C, 175°C, 175°C, 165°C, 165°C, 160°C, 160°C, the die temperature was 155°C, the rotation speed was 275rpm, the total residence time was 3min, and finally, underwater pelletizing was performed to obtain modified chlorinated polypropylene resin.

[0115] ATR spectrum of the modified chlorinated polypropylene resin prepared in this example: 561.8 cm -1 , 710.2cm -1 , 825.6cm -1 , 943.4cm -1 , 1140.5cm -1 , 1241.8cm -1 , 1370.3cm -1 , 1447.8cm -1 , 1516.2cm -1 , 1603.6cm -1 , 1724.3cm -1 , 2869.2cm -1 , 2920.4cm -1 , 2948.3cm -1 , 3181.6cm -1 , 3439.7cm -1 . 2400cm -1 ~1900cm -1 These are the mixed peaks of diamond and carbon dioxide in the atmosphere.

[0116] Example 6

[0117] 1) adding 270 parts of chlorinated polypropylene (Mw=130,000, chlorine content of 24% by mass) into 270 parts of toluene, heating to 75°C to completely dissolve the chlorinated polypropylene to form a chlorinated polypropylene liquid;

[0118] 2) adding 19.5 parts of sodium styrene sulfonate, 13.5 parts of styrene, and 24.6 parts of the intermediate into 260 parts of toluene, stirring at room temperature for 30 minutes, to obtain a grafting solution;

[0119] 3) dissolving 2.8 parts of dicumyl peroxide in 30 parts of toluene until completely dissolved to obtain an initiator solution;

[0120] 4) Under nitrogen protection, the chlorinated polypropylene liquid and the grafting liquid were mixed, the reaction temperature was raised to 70°C, and the initiator solution was added dropwise at a rate of 2 ml / min. After all the initiator solution was added, the reaction was continued for 2 h, and the solvent was removed under reduced pressure to obtain a grafted chlorinated polypropylene intermediate;

[0121] 5) 71.5 parts of grafted chlorinated polypropylene intermediate, 22.5 parts of xylene diisocyanate, 475 parts of carbon dioxide-based polyol (invention patent 201110231493.6, Example 8, Mn = 6000Da, Cu% = 34.3%) and 3.7 parts of trimethylolpropane were mixed and reacted at 80°C for 1.5h. Then the material was added to the twin screw, 0.7 parts of antioxidant 1098, 3.7 parts of butanediol and 0.8 parts of dibutyltin dilaurate were added, the screw process temperature was 130°C, 150°C, 165°C, 175°C, 175°C, 165°C, 165°C, 160°C, 160°C, the die temperature was 155°C, the rotation speed was 275rpm, the total residence time was 3min, and finally, underwater pelletizing was performed to obtain modified chlorinated polypropylene resin.

[0122] ATR spectrum of the modified chlorinated polypropylene resin prepared in this example: 562.4 cm -1 , 701.7cm -1 , 825.2cm -1 , 945.9cm -1 , 1130.7cm -1 , 1246.4cm -1 , 1371.8cm -1 , 1451.4cm -1 , 1516.8cm -1 , 1604.2cm -1 , 1725.9cm -1 , 2864.8cm -1 , 2918.4cm -1 , 2947.5cm -1 , 3184.2cm-1 , 3445.1cm -1 . 2400cm -1 ~1900cm -1 These are the mixed peaks of diamond and carbon dioxide in the atmosphere.

[0123] Comparative Example 1

[0124] This comparative example provides a method for preparing a chlorinated polypropylene emulsion system of a water-based primer resin for bumpers, specifically:

[0125] 1) adding 160 parts of chlorinated polypropylene (Mw: 100,000, chlorine content: 10%) to 30 parts of toluene and 350 parts of acetone, heating to 65° C. and stirring evenly to obtain chlorinated polypropylene liquid;

[0126] 2) adding 12.5 parts of maleic anhydride, 10.5 parts of butyl acrylate and 20.6 parts of acrylic acid to 50 parts of 180 parts of acetone and stirring at room temperature for 30 minutes to obtain a grafting solution;

[0127] 3) dissolving 2.1 parts of benzoyl peroxide in 20 parts of toluene until completely dissolved to obtain an initiator solution;

[0128] 4) Under nitrogen protection, the chlorinated polypropylene liquid and the grafting liquid were mixed, the reaction temperature was raised to 60°C, and the initiator solution was added dropwise at a drop rate of 1.5 ml / min. After all the initiator solution was added, the reaction was continued for 3 hours, the temperature was lowered to 30°C, 18 parts of triethylamine and 310 parts of deionized water were added, and the acetone was removed under reduced pressure to obtain the aqueous chlorinated polypropylene emulsion of this comparative example.

[0129] Depend on Figure 2 , 4 5, the SEM spectra of Example 1 and Example 2 clearly show that a tough filamentous structure appears in the cross-sectional structure of the resin, indicating that the resin has an excellent toughness structure and is a tough material, thereby ensuring the excellent adhesion of the obtained resin. Figure 5 ) does not show any filamentous structure, indicating that the material has poor toughness, is brittle and has poor adhesion.

[0130] Comparative Example 2

[0131] This comparative example provides a method for preparing a chlorinated polypropylene emulsion system of a water-based primer resin for bumpers, specifically:

[0132] 1) adding 160 parts of chlorinated polypropylene (Mw: 100,000, chlorine content: 10%) to 30 parts of toluene and 350 parts of acetone, heating to 65° C. and stirring evenly to obtain chlorinated polypropylene liquid;

[0133] 2) adding 12.5 parts of maleic anhydride, 10.5 parts of styrene and 20.6 parts of acrylic acid to 50 parts of 180 parts of acetone and stirring at room temperature for 30 minutes to obtain a grafting solution;

[0134] 3) dissolving 2.1 parts of benzoyl peroxide in 20 parts of toluene until completely dissolved to obtain an initiator solution;

[0135] 4) Under nitrogen protection, the chlorinated polypropylene liquid and the grafting liquid were mixed, the reaction temperature was raised to 60°C, and the initiator solution was added dropwise at a drop rate of 1.5 ml / min. After all the initiator solution was added, the reaction was continued for 3 hours, the temperature was lowered to 30°C, 18 parts of triethylamine and 310 parts of deionized water were added, and the acetone was removed under reduced pressure to obtain the aqueous chlorinated polypropylene emulsion of this comparative example.

[0136] Example 7

[0137] This embodiment provides a method for preparing an aqueous primer emulsion, specifically:

[0138] 20 parts of water-based primer resin (modified chlorinated polypropylene resin prepared in Example 1) were uniformly mixed with 60 parts of deionized water and 0.3 parts of sodium lauryl sulfate, and stirred at 85° C. and 1200 rpm for 30 minutes for emulsification. After the emulsification was completed, the mixture was cooled to room temperature and filtered with an 80-mesh filter to obtain a bumper water-based primer emulsion.

[0139] Example 8

[0140] This embodiment provides a method for preparing a water-based base paint for a bumper, specifically:

[0141] According to the formula in Table 1, the following steps were used to prepare the bumper water-based primer.

[0142] 1) Add titanium dioxide, carbon black, aqueous wetting dispersant and aqueous defoaming agent into a sand mill for sand grinding for 3 hours. When the fineness reaches 8 μm, introduce it into a high-speed disperser.

[0143] 2) Into a high-speed disperser, add the water-based primer resin (modified chlorinated polypropylene resin) / water-based chlorinated polypropylene emulsion of each embodiment and comparative example, a film-forming aid, an aqueous wetting and leveling agent, white carbon black and an aqueous curing agent, respectively, at a stirring rate of 400 rpm, and stir and mix at room temperature for 6 minutes to obtain water-based primer resins (modified chlorinated polypropylene resins) / water-based chlorinated polypropylene emulsions of different embodiments / comparative examples to prepare water-based primer paints for bumpers.

[0144] Table 1

[0145]

[0146]

[0147] The performance of the waterborne primer was tested, and the results are shown in Table 2.

[0148] Table 2

[0149]

[0150] In summary, it can be seen that the bumper water-based primer provided by the present invention has high hardness, non-sticky surface, can be activated at low temperature and does not require flame treatment. The bumper primer resin prepared by the present invention includes three components: the first component is a carbon dioxide-based polyol, and the carbonate and ether bond structure in the structure can improve the hydrolysis resistance of the water-based primer and improve the moisture and heat resistance of the primer resin; the second component is sodium styrene sulfonate in the structural formula and the rigid benzene ring structure of styrene, which improves the hardness of the water-based primer resin and the problem of stickiness on the paint film surface; the third component, the sodium styrene sulfonate group, ensures the water dispersibility of the primer resin.

[0151] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A modified chlorinated polypropylene resin, characterized in that: a. The main chain structure of the modified chlorinated polypropylene resin is chlorinated polypropylene, on whose side chains are grafted rigid structure styrene units, sodium styrene sulfonate units and carbon dioxide-based polyol structural units; b. The styrene unit and the sodium styrene sulfonate unit are grafted into the main chain structure by free radical polymerization, and the carbon dioxide-based polyol unit is connected to the main chain structure by a polyurethane reaction; c. The mass ratio of the chlorinated polypropylene to styrene, sodium styrene sulfonate and carbon dioxide-based polyol is 160 to 350: 10.5 to 14.8: 12.5 to 20.8: 420 to 510; d. The weight average molecular weight Mw of the chlorinated polypropylene is 100,000 to 250,000, wherein the mass content of chlorine is 10 to 30%.

2. The method for preparing the modified chlorinated polypropylene resin according to claim 1, characterized in that: include, 160-350 parts of chlorinated polypropylene and 200-400 parts of toluene are mixed and heated until the chlorinated polypropylene is completely dissolved to obtain a chlorinated polypropylene liquid; 12.5-20.8 parts of sodium styrene sulfonate, 10.5-14.8 parts of styrene, 20.6-30.5 parts of the intermediate, and 180-300 parts of toluene are mixed until completely dissolved to obtain a grafting solution; 2.1-3.6 parts of initiator and 20-45 parts of toluene are mixed until completely dissolved to obtain an initiator solution; Under the protection of nitrogen atmosphere, the chlorinated polypropylene liquid and the grafting liquid are mixed, the temperature is raised to 60-80°C, and the initiator solution is added dropwise, the reaction is continued for 1-3 hours, and the solvent is removed under reduced pressure to obtain a grafted chlorinated polypropylene intermediate; 50.8-81.6 parts of grafted chlorinated polypropylene intermediate, 18.5-23.7 parts of diisocyanate, 420-510 parts of carbon dioxide-based polyol and 3.5-4.2 parts of trimethylolpropane are uniformly mixed and reacted at 70-85°C for 1-2 hours, and then 0.3-0.8 parts of antioxidant, 2.4-4.1 parts of butanediol and 0.3-0.8 parts of catalyst are added, twin-screw melt extrusion is carried out, and underwater pelletizing is carried out to obtain modified chlorinated polypropylene resin.

3. The method for preparing the modified chlorinated polypropylene resin according to claim 2, characterized in that: The preparation method of the intermediate, include, 100-110 parts of maleic anhydride and 140-150 parts of 1-naphthylamine are mixed and added with xylene, 0.1-0.5 parts of hydroquinone and 0.5-1.0 parts of p-toluenesulfonic acid, and reacted at 120-150°C for 4-8 hours, then 30% sodium carbonate solution is added, and the mixture is allowed to stand for stratification, and the xylene layer is washed and dried, and the xylene is removed under reduced pressure to obtain an intermediate precursor; The intermediate precursor is dissolved in isopropanol, and sodium borohydride is added in five batches. After all the sodium borohydride is added, the temperature is raised to 55-75°C, and the reaction is carried out for 3-5 hours. The temperature is then lowered to room temperature, deionized water is added, and the mixture is stirred for 15 minutes. After the pH value is adjusted to neutral, the isopropanol and deionized water are evaporated under reduced pressure, deionized water and methylcyclohexane are added, and the mixture is stirred at room temperature for 15-20 minutes. The mixture is allowed to stand and separate into layers, and the methylcyclohexane organic layer is retained. The mixture is washed, dried, and the solvent is removed to obtain the intermediate.

4. The method for preparing the modified chlorinated polypropylene resin according to claim 2, characterized in that: The dropping rate of the initiator is 1.5-4.0 ml / min.

5. The method for preparing the modified chlorinated polypropylene resin according to claim 2, characterized in that: The initiator includes one or more of benzoyl peroxide, dicumyl peroxide, dilauroyl peroxide, 1,1-di(tert-butylperoxy)3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butyl peroxyacetate, tert-amyl peroxy 2-ethylhexanoate, and dilauroyl peroxide; The diisocyanate includes one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and xylylene diisocyanate.

6. The method for preparing the modified chlorinated polypropylene resin according to claim 2, characterized in that: The number average molecular weight of the carbon dioxide-based polyol is 3300 to 6000, and the unit content is 30.6 to 54.8%; The antioxidant includes one or more of hindered phenols and phosphite antioxidants, including one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 1790, and antioxidant 168; The catalyst is an organic metal catalyst, including one or more of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate.

7. The method for preparing the modified chlorinated polypropylene resin according to claim 2, characterized in that: The twin-screw melt extrusion, wherein the process temperature of each section of the screw is 120-130°C, 145-155°C, 160-170°C, 170-180°C, 170-180°C, 170-180°C, 160-170°C, 160-170°C, 155-165°C, 155-165°C, the die head temperature is 150-160°C, the rotation speed is 200-300rpm, and the total time is 2-4min.

8. Use of the modified chlorinated polypropylene resin according to claim 1 in preparing a water-based primer for a bumper, characterized in that: The bumper water-based primer includes one of a water-based primer paint and a water-based primer emulsion.

9. A water-based primer, characterized in that: The preparation method thereof comprises: 260-400 parts of titanium dioxide, 5-12 parts of carbon black, 2-8 parts of water-based wetting and dispersing agent, and 4-7 parts of water-based defoaming agent are mixed and sand-milled for 2-4 hours. When the fineness reaches 8 μm, 1680-2850 parts of the modified chlorinated polypropylene resin according to claim 1, 160-220 parts of film-forming aid, 1.5-4 parts of water-based wetting and leveling agent, 3-5 parts of white carbon black and 28-45 parts of water-based curing agent are added. The mixture is stirred at a high speed of 300-500 rpm for 5-8 minutes to obtain a water-based base coating for bumpers.

10. A water-based primer emulsion, characterized in that: The preparation method thereof comprises: 15-25 parts of the modified chlorinated polypropylene resin according to claim 1 are uniformly mixed with 55-65 parts of deionized water and 0.1-0.5 parts of sodium dodecyl sulfate, and emulsified at 80-90° C. with stirring; after the emulsification is completed, the mixture is cooled to room temperature to obtain a bumper water-based primer emulsion; The stirring speed is 1100-1300 rpm, and the stirring time is 20-40 min.

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