Hyperbranched polyester modified acrylic monomer, modified polyacrylate and polyacrylate adhesive as well as preparation method and application thereof

Abstract

The invention provides a hyperbranched polyester modified acrylic monomer, modified polyacrylate and a polyacrylate adhesive as well as a preparation method and application thereof, and belongs to the technical field of adhesives. The hyperbranched polyester modified acrylic monomer provided by the invention has a chemical structure shown in the specification. As a macromolecular structure, the hyperbranched polyester modified polyacrylic acid monomer disclosed by the invention can form a hydrogen bond with polyacrylate, and the molecular weight and crosslinking degree of the modified polyacrylate can be improved, so that the diffusion of a plasticizer is limited, and the plasticizer-resistant effect of the polyacrylate is enhanced. The hyperbranched polyester provided by the invention modifies the polyacrylate structure, so that the chain segment flexibility of the polyacrylate is improved, the molecular weight of the polyacrylate is increased, the crosslinking degree of the polyacrylate is improved due to the macromolecular structure, the cohesion of the polyacrylate is improved, and the weather resistance of the polyacrylate is enhanced. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and specifically relates to a hyperbranched polyester modified acrylic monomer, modified polyacrylate and polyacrylate adhesive, and a preparation method and application thereof. Background Art

[0002] Car covers are a kind of protective film that is attached to the surface of car paint using high molecular polymer materials to protect the original paint and decorate the car body. It can be easily removed at any time without damaging the original paint. Pressure-sensitive adhesive is an adhesive that can adhere to the surface of an object under slight pressure without the need for additional heating or solvent treatment. It is usually used to bond car covers. The main materials of car covers are PVC, TPH and TPU. Certain plasticizers are added during the production process to improve their softness and elasticity, making them easier to operate during construction. However, the addition of plasticizers will destroy the performance of the pressure-sensitive adhesive used for car covers. After long-term use, the precipitation of plasticizers will cause the adhesion performance of the pressure-sensitive adhesive to decrease, resulting in degumming. When replacing car covers, residual glue and degumming will also occur.

[0003] The paint protection film made of TPU material has the characteristics of high tensile strength and excellent aging resistance, but the surface energy of TPU material is low, and it is difficult to achieve good adhesion using conventional adhesives, which can easily cause problems such as debonding of the protective film. In addition, the car cover is an external film, and changes in high and low temperature environments will have a great impact on the service life of the pressure-sensitive adhesive of the protective film, especially when the temperature difference between day and night is large outdoors, which will cause the molecular chain segment of the pressure-sensitive adhesive of the paint protection film to break and residual adhesive to appear.

[0004] For example, there is a prior art that discloses an emulsion type acrylic pressure-sensitive adhesive and a preparation method thereof, which specifically uses acrylic ester monomers as raw materials, and introduces hydrogenated rosin and then allyloxy nonylphenol, so that the provided pressure-sensitive adhesive has high initial adhesion and high peel strength. However, when the pressure-sensitive adhesive is actually used for car covers, there is a defect of a large amount of residual adhesive and its weather resistance needs to be further improved. Summary of the invention

[0005] The purpose of the present invention is to provide a hyperbranched polyester modified acrylic monomer, modified polyacrylate and polyacrylate adhesive and a preparation method and application thereof. The polyacrylate adhesive prepared by using the hyperbranched polyester modified acrylic monomer and modified polyacrylate provided by the present invention has excellent weather resistance and less residual adhesive when used in invisible car cover.

[0006] In order to achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0007] A hyperbranched polyester modified acrylic monomer having the following chemical structure:

[0008]

[0009] The present invention also provides a method for preparing the hyperbranched polyester modified acrylic monomer of the above technical solution, comprising the following steps:

[0010] The terminal hydroxyl hyperbranched polyester and acrylic acid are subjected to an esterification reaction under an acid catalyst condition to obtain the hyperbranched polyester modified acrylic acid monomer;

[0011] The hyperbranched polyester has the following chemical structure:

[0012]

[0013] Preferably, the molar ratio of the hyperbranched polyester to acrylic acid is 1:4-8.

[0014] Preferably, the esterification reaction is carried out at a temperature of 60 to 100° C. and for a time of 6 to 8 hours.

[0015] The present invention also provides a modified polyacrylate having the following chemical structure:

[0016]

[0017] Wherein, R is an alkyl group having 1 to 12 carbon atoms;

[0018] The raw materials for preparing the modified polyacrylate include, by weight:

[0019] 70-90 parts of acrylic acid ester soft monomer, 5-10 parts of hyperbranched polyester modified acrylic acid monomer described in the above technical solution, 1-5 parts of acrylic acid hard monomer, 1-2 parts of acrylic acid functional monomer, 0.1-0.3 parts of initiator and 50-60 parts of organic solvent.

[0020] Preferably, the acrylic acid ester soft monomer includes one or more of butyl acrylate, isooctyl acrylate, ethyl acrylate and lauryl methacrylate.

[0021] Preferably, the acrylic hard monomer includes one or more of acrylic acid, methyl acrylate, methyl methacrylate and vinyl acetate.

[0022] Preferably, the acrylic functional monomer includes one or more of acrylamide, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl methacrylate, isobornyl acrylate and isobornyl methacrylate.

[0023] The present invention also provides a polyacrylate adhesive, the preparation raw materials of which include the modified polyacrylate and polyacrylate described in the above technical solution; the mass ratio of the modified polyacrylate to the polyacrylate is 2-3:7-8.

[0024] The present invention also provides the use of the polyacrylate adhesive described in the above technical solution in the pressure-sensitive adhesive for invisible car cover.

[0025] The invention provides a hyperbranched polyester modified acrylic monomer having a chemical structure as shown below. As a macromolecular structure, the hyperbranched polyester modified polyacrylic monomer of the invention can form hydrogen bonds with polyacrylate, thereby increasing the molecular weight and crosslinking degree of the modified polyacrylate, thereby limiting the diffusion of plasticizers and enhancing the plasticizer resistance of the polyacrylate.

[0026] The present invention also provides a modified polyacrylate. The hyperbranched polyester modified polyacrylate structure provided by the present invention is a flexible segment, which can improve the segment flexibility of the polyacrylate and increase the molecular weight of the polyacrylate. The macromolecular structure improves the crosslinking degree of the polyacrylate and the cohesive force of the polyacrylate, thereby enhancing the weather resistance of the polyacrylate itself; at the same time, the bonding force between the polyacrylate adhesive and the invisible car cover substrates such as TPU / PVC is improved; and the improvement of the segment crosslinking degree can increase the cohesive force of the glue, and the segment of the glue itself is not easily destroyed, which can greatly reduce the problems of degumming and residual glue during use, thereby extending the service life of the invisible car cover. DETAILED DESCRIPTION

[0027] The present invention provides a hyperbranched polyester modified acrylic monomer having the following chemical structure:

[0028]

[0029] In the present invention, the chemical structure of the hyperbranched polyester modified acrylic monomer is the number of acrylic acid connected in the terminal hydroxyl hyperbranched polyester.

[0030] The present invention also provides a method for preparing the hyperbranched polyester modified acrylic monomer described in the above technical solution, comprising the following steps:

[0031] The terminal hydroxyl hyperbranched polyester and acrylic acid are subjected to an esterification reaction under an acid catalyst condition to obtain the hyperbranched polyester modified acrylic acid monomer;

[0032] The hyperbranched polyester has the following chemical structure:

[0033]

[0034] In the present invention, unless otherwise specified, all the raw materials for preparation of the present invention are commercially available products well known to those skilled in the art or are prepared by preparation methods well known to those skilled in the art.

[0035] In the present invention, the synthetic route of the hyperbranched polyester is as follows:

[0036]

[0037] In the present invention, the acid catalyst includes hydrochloric acid, sulfuric acid solution or nitric acid solution, and in a specific embodiment, it can be hydrochloric acid; the concentration of the acid catalyst is 5-20wt%, and in a specific embodiment, it can be 8wt% or 10wt%.

[0038] In the present invention, the molar ratio of the hyperbranched polyester to acrylic acid is 1:4-8, and in specific embodiments, it can be 1:5, 1:6 or 1:7.

[0039] In the present invention, the temperature of the esterification reaction is 60-100°C, and in a specific embodiment, it can be 70°C, 75°C, 82°C, 85°C, 88°C or 95°C, and the time is 6-8h, and in a specific embodiment, it can be 7h or 7.5h.

[0040] The present invention also provides a modified polyacrylate having the following chemical structure:

[0041]

[0042] Wherein, R is an alkyl group having 1 to 12 carbon atoms;

[0043] The raw materials for preparing the modified polyacrylate include, by weight:

[0044] 70-90 parts of acrylic soft ester monomer, 5-10 parts of the hyperbranched polyester modified acrylic monomer described in the above technical solution, 1-5 parts of acrylic hard monomer, 1-2 parts of acrylic functional monomer, 0.1-0.3 parts of initiator and 50-60 parts of organic solvent.

[0045] In the present invention, R is the structure of the acrylic soft monomer except the ester group; R is an alkyl group having 1 to 12 carbon atoms, and in a specific embodiment, it can be ethyl, butyl, isooctyl or dodecyl; a is the degree of polymerization of the modified polyacrylate, and the present invention has no special limitation on the degree of polymerization of the modified polyacrylate.

[0046] In the present invention, the raw materials for preparing the modified polyacrylate include 70 to 90 parts of acrylic acid ester soft monomers, and in a specific embodiment, can be 75 parts, 80 parts or 85 parts; the acrylic acid soft monomers include one or more of butyl acrylate, isooctyl acrylate, ethyl acrylate and lauryl methacrylate, and in a specific embodiment, can be butyl acrylate and isooctyl acrylate, butyl acrylate and lauryl acrylate.

[0047] In the present invention, the raw materials for preparing the modified polyacrylate include 1 to 5 parts of acrylic hard monomers, and in a specific embodiment, can be 2 parts or 4 parts; the acrylic hard monomer includes one or more of acrylic acid, methyl acrylate, methyl methacrylate and vinyl acetate, and in a specific embodiment, can be acrylic acid.

[0048] In the present invention, the raw materials for preparing the modified polyacrylate include 5 to 10 parts of hyperbranched polyester modified acrylic monomers, and in specific embodiments, can be 6 parts, 7 parts or 8 parts. As a macromolecular structure, the hyperbranched polyester modified polyacrylic monomer of the present invention can form hydrogen bonds with polyacrylate, which can increase the molecular weight and crosslinking degree of the modified polyacrylate, thereby limiting the diffusion of plasticizers and enhancing the plasticizer resistance of polyacrylate.

[0049] In the present invention, the raw materials for preparing the modified polyacrylate include 1 to 5 parts of acrylic acid, and in a specific embodiment, it can be 2 parts, 3 parts or 4 parts.

[0050] In the present invention, the raw materials for preparing the modified polyacrylate include 1 to 2 parts of acrylic functional monomers, and in a specific embodiment, it can be 1.5 parts; the acrylic functional monomers include one or more of acrylamide, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl methacrylate, isobornyl acrylate and isobornyl methacrylate, and in a specific embodiment, it can be isobornyl acrylate or 2-hydroxyethyl acrylate.

[0051] In the present invention, the raw materials for preparing the modified polyacrylate include 0.1 to 0.3 parts of an initiator, and in a specific embodiment, it can be 0.2 parts; the initiator includes one or more of dibenzoyl peroxide, azobisisobutyronitrile and azobisisoheptylnitrile, and in a specific embodiment, it can be dibenzoyl peroxide.

[0052] In the present invention, the raw materials for preparing the modified polyacrylate include 50 to 60 parts of an organic solvent, and in a specific embodiment, can be 53 parts, 55 parts or 58 parts; the organic solvent includes one or more of ethyl acetate, methyl acetate, toluene, acetone and butanone, and in a specific embodiment, can be acetone, ethyl acetate and toluene.

[0053] In the present invention, the preparation method of modified polyacrylate comprises: mixing the raw materials for preparing the modified polyacrylate, and performing free radical polymerization to obtain the modified polyacrylate; the temperature of the free radical polymerization is 80-90° C., and the time is 8-16 hours.

[0054] The present invention also provides a polyacrylate adhesive, the preparation raw materials of which include the modified polyacrylate and polyacrylate described in the above technical solution; the mass ratio of the modified polyacrylate to the polyacrylate is 2-3:7-8.

[0055] In the present invention, the polyacrylate comprises the following preparation raw materials:

[0056] The acrylic soft monomer is 60-80 parts, the acrylic hard monomer is 5-15 parts, the acrylic functional monomer is 1-5 parts, the initiator is 0.5-1 part and the organic solvent is 50-70 parts.

[0057] The acrylic soft monomer, acrylic hard monomer, acrylic functional monomer, initiator and organic solvent described in the present invention are the same as the acrylic soft monomer, acrylic hard monomer, acrylic functional monomer, initiator and organic solvent described above, and are not described in detail here.

[0058] In the present invention, the preparation method of the polyacrylate comprises the following steps:

[0059] Mixing acrylic soft monomer, acrylic hard monomer and acrylic functional monomer to obtain a mixed solution A;

[0060] Mixing an organic solvent and an initiator to obtain a mixed solution B;

[0061] One half of the mixed solution A and one third of the mixed solution B are mixed to carry out a first initiation polymerization, and then one half of the mixed solution A and one third of the mixed solution B are added to carry out heat preservation polymerization, and then one third of the mixed solution B is added to carry out a second initiation polymerization to obtain the polyacrylate.

[0062] In the present invention, the mixture is added to a constant pressure dropping funnel, mixed evenly, and then added to the reaction kettle by dropwise addition, and the dropwise addition time is controlled to be 2 hours. After the dropwise addition is completed, heat preservation polymerization is performed, and the heat preservation time is 6 hours.

[0063] In the present invention, the method of adding one half of the mixed liquid A and one third of the mixed liquid B is dropwise addition, and the dropwise addition time is 2 to 4 hours, and in a specific embodiment, it can be 2.5 or 3 hours; the temperature of the first initiation polymerization, the heat preservation polymerization and the second initiation polymerization is independently 80 to 90°C, and in a specific embodiment, it can be 82, 85°C or 88°C; the time of the first initiation polymerization and the second initiation polymerization is independently 0.5 to 3 hours, and in a specific embodiment, it can be 1 hour, 1.5 hours, 2 hours or 2.5 hours; the time of the heat preservation polymerization is 4 to 8 hours, and in a specific embodiment, it can be 5 hours, 6 hours or 7 hours.

[0064] In the present invention, the mass ratio of the modified polyacrylate to the polyacrylate is 1-3:7-9, and in a specific embodiment, it can be 2:8, 3:7 or 1.5:8.5.

[0065] In the present invention, the polyacrylate adhesive further includes a curing agent; the curing agent is an isocyanate curing agent.

[0066] The present invention also provides the use of the polyacrylate adhesive described in the above technical solution in the pressure-sensitive adhesive for invisible car cover.

[0067] To further illustrate the present invention, the hyperbranched polyester modified acrylic monomer, modified polyacrylate and polyacrylate adhesive provided by the present invention and their preparation methods and applications are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0068] Example 1

[0069] Weigh a hyperbranched polyester and acrylic acid in a molar ratio of 1:4 and place them in a reaction kettle, stir them evenly, and react them at 85° C. and 5 wt % HCl catalyst for 6 hours to obtain a hyperbranched polyester modified acrylic acid monomer;

[0070] 70 parts of butyl acrylate, 10 parts of isooctyl acrylate, 5 parts of hyperbranched polyester modified acrylic monomer, 2 parts of acrylic acid, 1 part of 2-hydroxyethyl acrylate, 0.1 part of dibenzoyl peroxide, 50 parts of ethyl acetate and 10 parts of toluene were weighed by weight and reacted at 80° C. for 10 hours to obtain modified polyacrylate.

[0071] Example 2

[0072] Weigh a hyperbranched polyester and acrylic acid in a molar ratio of 1:4 and place them in a reaction kettle, stir them evenly, and react them at 85° C. and 5 wt % HCl catalyst for 6 hours to obtain a hyperbranched polyester modified acrylic acid monomer;

[0073] 75 parts of butyl acrylate, 5 parts of lauryl acrylate, 6 parts of hyperbranched polyester modified acrylic monomer, 1 part of acrylic acid, 1 part of glycidyl methacrylate, 0.1 part of dibenzoyl peroxide and 60 parts of ethyl acetate were weighed by weight and reacted at 80° C. for 10 hours to obtain modified polyacrylate.

[0074] Example 3

[0075] Weigh hyperbranched polyester and acrylic acid in a molar ratio of 1:6 into a reaction kettle, stir evenly, and react at 85° C. and 5 wt % HCl catalyst for 7 h to obtain a hyperbranched polyester modified acrylic acid monomer;

[0076] Weigh 75 parts of butyl acrylate, 5 parts of isooctyl acrylate, 7 parts of hyperbranched polyester modified acrylic monomer, 2 parts of acrylic acid, 1 part of 2-hydroxyethyl acrylate, 0.1 parts of azobisisoheptonitrile, 10 parts of methyl acetate and 40 parts of ethyl acetate by weight, and react at 80°C for 10 hours to obtain modified polyacrylate.

[0077] Example 4

[0078] Weigh a hyperbranched polyester and acrylic acid in a molar ratio of 1:5 and place them in a reaction kettle, stir them evenly, and react them at 85° C. and 5 wt % HCl catalyst for 7 h to obtain a hyperbranched polyester modified acrylic acid monomer;

[0079] Weigh 75 parts of butyl acrylate, 5 parts of isooctyl acrylate, 7 parts of hyperbranched polyester modified acrylic monomer, 2 parts of acrylic acid, 1 part of 2-hydroxyethyl acrylate, 0.1 parts of azobisisoheptonitrile, 10 parts of methyl acetate and 40 parts of ethyl acetate by weight, and react at 80°C for 10 hours to obtain modified polyacrylate.

[0080] Example 5

[0081] Weigh a hyperbranched polyester and acrylic acid in a molar ratio of 1:8 and place them in a reaction kettle, stir them evenly, and react them at 85° C. and 5 wt % HCl catalyst for 8 h to obtain a hyperbranched polyester modified acrylic acid monomer;

[0082] 70 parts of butyl acrylate, 5 parts of lauryl acrylate, 10 parts of hyperbranched polyester modified acrylic monomer, 1 part of acrylic acid, 1 part of glycidyl methacrylate, 0.2 parts of dibenzoyl peroxide, 10 parts of acetone, 40 parts of ethyl acetate and 5 parts of toluene were weighed by weight and reacted at 80° C. for 10 hours to obtain modified polyacrylate.

[0083] Example 6

[0084] Weigh a hyperbranched polyester and acrylic acid in a molar ratio of 1:6 into a reaction kettle, stir evenly, and react at 85° C. and 5 wt % HCl catalyst for 6 h to obtain a hyperbranched polyester modified acrylic acid monomer;

[0085] 70 parts of butyl acrylate, 15 parts of lauryl acrylate, 8 parts of hyperbranched polyester modified acrylic monomer, 1 part of acrylic acid, 1 part of isobornyl acrylate, 0.1 parts of azobisisoheptonitrile and 50 parts of ethyl acetate were weighed by weight and reacted at 80° C. for 10 hours to obtain hyperbranched polyester modified polyacrylate.

[0086] Example 7

[0087] Weigh 40 parts of butyl acrylate, 30 parts of isooctyl acrylate, 5 parts of acrylic acid, 3 parts of vinyl acetate, and 1 part of 2-hydroxyethyl acrylate by weight and mix them to obtain a mixed solution A; weigh 0.5 parts of dibenzoyl peroxide, 50 parts of ethyl acetate, and 10 parts of toluene and mix them to obtain a mixed solution B;

[0088] Take one half of the mixed solution A and one third of the mixed solution B and add them into the reactor, stir and heat to 82°C, and carry out the first initiation polymerization for 0.5h;

[0089] The remaining mixed solution A and one third of the mixed solution B are added to a constant pressure dropping funnel, mixed evenly and then added to the reactor by dropwise addition, the dropping time is controlled to be 2 hours, and after the dropping is completed, heat preservation polymerization is carried out for 6 hours. After the polymerization is completed, the remaining one third of the mixed solution B is added to a constant pressure dropping funnel, and added dropwise to the reactor, the dropping time is controlled to be 1 hour, and the second initiation polymerization is carried out for 2 hours, and the temperature is lowered to 50°C, and the material is discharged to obtain polyacrylate;

[0090] According to weight proportions, 10 parts of the hyperbranched polyester modified polyacrylate obtained in Example 1 and 90 parts of polyacrylate were weighed, mixed evenly, and then 0.5 parts of a crosslinking agent was added, and mixed evenly to obtain a polyacrylate adhesive.

[0091] Example 8

[0092] Weigh 50 parts of butyl acrylate, 20 parts of isooctyl acrylate, 5 parts of lauryl acrylate, 6 parts of acrylic acid and 1 part of 2-hydroxyethyl acrylate by weight and mix them to obtain a mixed solution A; weigh 0.6 parts of dibenzoyl peroxide and 70 parts of ethyl acetate and mix them to obtain a mixed solution B;

[0093] Take one half of the mixed solution A and one third of the mixed solution B and add them into the reactor, stir and heat to 84°C, and carry out the first initiation polymerization for 1 hour;

[0094] The remaining mixed solution A and one third of the mixed solution B are added to the constant pressure dropping funnel, mixed evenly and then added to the reactor by dropwise addition, the dropping time is controlled to be 2.5 hours, and after the dropping is completed, heat preservation polymerization is carried out for 7 hours. After the polymerization is completed, the remaining one third of the mixed solution B is added to the constant pressure dropping funnel, and added dropwise to the reactor, the dropping time is controlled to be 2 hours, and the second initiation polymerization is carried out for 2 hours, and the temperature is lowered to 50°C, and the material is discharged to obtain polyacrylate;

[0095] According to weight proportions, 15 parts of the hyperbranched polyester modified polyacrylate obtained in Example 2 and 85 parts of polyacrylate were weighed, mixed evenly, and then 0.5 parts of a crosslinking agent was added, and mixed evenly to obtain a polyacrylate adhesive.

[0096] Example 9

[0097] Weigh 45 parts of butyl acrylate, 25 parts of isooctyl acrylate, 3 parts of acrylic acid, 10 parts of methyl acrylate and 2 parts of glycidyl methacrylate by weight and mix to obtain a mixed solution A; weigh 0.8 parts of azobisisoheptanenitrile, 10 parts of acetone, 40 parts of ethyl acetate and 10 parts of toluene and mix to obtain a mixed solution B;

[0098] Take one half of the mixed solution A and one third of the mixed solution B and add them into the reactor, stir and heat to 82°C, and carry out the first initiation polymerization for 0.5h;

[0099] The remaining mixed solution A and one third of the mixed solution B are added to a constant pressure dropping funnel, mixed evenly and then added to the reactor by dropwise addition, the dropping time is controlled to be 3 hours, and after the dropping is completed, heat preservation polymerization is carried out for 7 hours. After the polymerization is completed, the remaining one third of the mixed solution B is added to a constant pressure dropping funnel, and added dropwise to the reactor, the dropping time is controlled to be 2 hours, and the second initiation polymerization is carried out for 1 hour, and the temperature is lowered to 50°C, and the material is discharged to obtain polyacrylate;

[0100] 15 parts of the hyperbranched polyester modified polyacrylate obtained in Example 3 and 85 parts of polyacrylate were weighed by weight, mixed evenly, and then 0.5 parts of a cross-linking agent was added and mixed evenly to obtain a polyacrylate adhesive.

[0101] Example 10

[0102] Weigh 60 parts of isooctyl acrylate, 5 parts of lauryl acrylate, 10 parts of methyl methacrylate, 3 parts of acrylic acid and 2 parts of acrylamide by weight to obtain a mixed solution A; weigh 0.6 parts of azobisisoheptanenitrile, 50 parts of ethyl acetate and 20 parts of butanone to obtain a mixed solution B;

[0103] Take one half of the mixed solution A and one third of the mixed solution B and add them into the reactor, stir and heat to 88°C, and carry out the first initiation polymerization for 0.5h;

[0104] The remaining mixed solution A and one third of the mixed solution B are added to a constant pressure dropping funnel, mixed evenly and then added to the reactor by dropwise addition, the dropping time is controlled to be 4 hours, and after the dropping is completed, heat preservation polymerization is carried out for 8 hours. After the polymerization is completed, the remaining one third of the mixed solution B is added to a constant pressure dropping funnel, and added dropwise to the reactor, the dropping time is controlled to be 1 hour, and the second initiation polymerization is carried out for 1.5 hours, and the temperature is lowered to 50°C, and the material is discharged to obtain polyacrylate;

[0105] According to weight proportions, 20 parts of the hyperbranched polyester modified polyacrylate obtained in Example 4 and 80 parts of polyacrylate were weighed, mixed evenly, and then 1 part of a cross-linking agent was added and mixed evenly to obtain a polyacrylate adhesive.

[0106] Embodiment 11

[0107] Weigh 50 parts of butyl acrylate, 10 parts of isooctyl acrylate, 2 parts of acrylic acid, 10 parts of methyl acrylate and 1 part of isobornyl acrylate by weight and mix them to obtain a mixed solution A; weigh 0.5 parts of azobisisoheptanenitrile, 30 parts of methyl acetate and 30 parts of toluene and mix them to obtain a mixed solution B;

[0108] Take one half of the mixed solution A and one third of the mixed solution B and add them into the reactor, stir and heat to 88°C, and carry out the first initiation polymerization for 1 hour;

[0109] The remaining mixed solution A and one third of the mixed solution B are added to a constant pressure dropping funnel, mixed evenly and then added to the reactor by dropwise addition, the dropping time is controlled to be 3 hours, and after the dropping is completed, heat preservation polymerization is carried out for 7 hours. After the polymerization is completed, the remaining one third of the mixed solution B is added to a constant pressure dropping funnel, and added dropwise to the reactor, the dropping time is controlled to be 2 hours, and the second initiation polymerization is carried out for 4 hours, and the temperature is lowered to 50°C, and the material is discharged to obtain polyacrylate;

[0110] According to weight proportions, 30 parts of the hyperbranched polyester modified polyacrylate obtained in Example 5 and 70 parts of polyacrylate were weighed, mixed evenly, and then 1 part of a cross-linking agent was added and mixed evenly to obtain a polyacrylate adhesive.

[0111] Example 12

[0112] Weigh 70 parts of butyl acrylate, 5 parts of acrylic acid, 8 parts of methyl acrylate, 1 part of isobornyl acrylate and 1 part of 2-hydroxyethyl acrylate in parts by weight and mix to obtain a mixed solution A; weigh 0.5 parts of azobisisoheptanenitrile, 30 parts of ethyl acetate and 20 parts of toluene and mix to obtain a mixed solution B;

[0113] Take one half of the mixed solution A and one third of the mixed solution B and add them into the reactor, stir and heat to 88°C, and carry out the first initiation polymerization for 0.5h;

[0114] The remaining mixed solution A and one third of the mixed solution B are added to a constant pressure dropping funnel, mixed evenly and then added to the reactor by dropwise addition, the dropping time is controlled to be 3 hours, and after the dropping is completed, heat preservation polymerization is carried out for 7 hours. After the polymerization is completed, the remaining one third of the mixed solution B is added to a constant pressure dropping funnel, and added dropwise to the reactor, the dropping time is controlled to be 1 hour, and the second initiation polymerization is carried out for 2 hours, and the temperature is lowered to 50°C, and the material is discharged to obtain polyacrylate;

[0115] According to weight percentage, 20 parts of the hyperbranched polyester modified polyacrylate obtained in Example 6 and 80 parts of polyacrylate were weighed, mixed evenly, and then 1 part of a cross-linking agent was added and mixed evenly to obtain a polyacrylate adhesive.

[0116] Test Case

[0117] The polyacrylate adhesive obtained in Examples 7 to 12 was coated on a release film, and then transferred to a TPU film after being baked at 130° C. for 3 minutes. The performance was tested after being attached to a silicone oil film. The test results are shown below.

[0118] Table 1 Performance test results of polyacrylate adhesives obtained in Examples 7 to 12

[0119]

[0120] It can be seen from the results in Table 1 that the hyperbranched polyester modified polyacrylate prepared in the present invention has high initial adhesion. After the aging experiment, the viscosity decreases. The adhesion test shows that the glue has good adhesion and is not easy to leave residual glue.

[0121] The peel strength after double 85 reflects its excellent weather resistance, and also shows that the glue prepared by the present invention still has excellent performance after long-term use, and will not debond.

[0122] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A hyperbranched polyester modified acrylic monomer, characterized in that: It has the following chemical structure:

2. The method for preparing the hyperbranched polyester modified acrylic monomer according to claim 1, characterized in that: The following steps are involved: The terminal hydroxyl hyperbranched polyester and acrylic acid are subjected to an esterification reaction under an acid catalyst condition to obtain the hyperbranched polyester modified acrylic acid monomer; The hyperbranched polyester has the following chemical structure:

3. The preparation method according to claim 2, characterized in that: The molar ratio of the hyperbranched polyester to acrylic acid is 1:4-8.

4. The preparation method according to claim 2 or 3, characterized in that: The temperature of the esterification reaction is 60-100° C. and the time is 6-8 hours.

5. A modified polyacrylate, characterized in that: It has the following chemical structure: Wherein, R is an alkyl group having 1 to 12 carbon atoms; The raw materials for preparing the modified polyacrylate include, by weight: 70-90 parts of acrylic acid ester soft monomer, 5-10 parts of the hyperbranched polyester modified acrylic acid monomer according to claim 1, 1-5 parts of acrylic acid hard monomer, 1-2 parts of acrylic acid functional monomer, 0.1-0.3 parts of initiator and 50-60 parts of organic solvent.

6. The modified polyacrylate according to claim 5, characterized in that: The acrylic acid ester soft monomer includes one or more of butyl acrylate, isooctyl acrylate, ethyl acrylate and lauryl methacrylate.

7. The modified polyacrylate according to claim 5, characterized in that: The acrylic hard monomer includes one or more of acrylic acid, methyl acrylate, methyl methacrylate and vinyl acetate.

8. The modified polyacrylate according to claim 5, characterized in that: The acrylic functional monomer includes one or more of acrylamide, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl methacrylate, isobornyl acrylate and isobornyl methacrylate.

9. A polyacrylate adhesive, characterized in that: The preparation raw materials include the modified polyacrylate and polyacrylate described in any one of claims 5 to 8; the mass ratio of the modified polyacrylate to the polyacrylate is 2 to 3:7 to 8.

10. Use of the polyacrylate adhesive according to claim 9 in pressure-sensitive adhesive for invisible car cover.

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