Castor oil-based polyurethane acrylate prepolymer, UV adhesive, and preparation method and application of castor oil-based polyurethane acrylate prepolymer and UV adhesive

Abstract

The invention discloses a castor oil-based polyurethane acrylate prepolymer, a UV (ultraviolet) adhesive as well as a preparation method and application of the castor oil-based polyurethane acrylate prepolymer. The castor oil-based polyurethane acrylate prepolymer at least comprises the following structural formula: # imgabs 0 #, wherein R1 is selected from any one of the following groups: # imgabs 1 #, and a monomer structure corresponding to # imgabs 2 # before reaction is a diisocyanate monomer; and R2 is selected from a structure obtained by removing H atoms from hydroxyl in a hydroxyl acrylate monomer. The UV adhesive comprises a monomer, a photoinitiator, a prepolymer, a coupling agent and an auxiliary agent. The adhesive disclosed by the invention is good in adhesion firmness, small in volume shrinkage, good in heat resistance, water resistance and chemical resistance, and has the advantages of cheap and easily available raw materials, green, environment-friendly and the like. The adhesive system disclosed by the invention can be used for producing and preparing disposable sterile syringe needles.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and more particularly to a castor oil-based polyurethane acrylate prepolymer, a UV adhesive, and a preparation method and application thereof. Background Art

[0002] Ultraviolet light curing (i.e. UV curing) uses light energy as energy, does not produce greenhouse gases, and uses less solvent. It is an energy-saving and environmentally friendly industrial technology that emerged in the 1960s. Its principle is that the photoinitiator (photosensitizer) in the system forms excited molecules under ultraviolet light irradiation, which are further decomposed into free radicals or ions to cause the unsaturated organic matter in the system to undergo chemical reactions such as polymerization, grafting, and cross-linking to achieve the purpose of curing. UV-curing adhesives have the advantages of low VOC emissions, low energy consumption, room temperature curing, and fast curing speed. They are green and environmentally friendly adhesives and have been widely used in the fields of optoelectronic device preparation, building materials, and medical materials. Among them, the research on acrylic adhesives is particularly active.

[0003] Acrylic adhesives have good film-forming and light-resistant properties. However, due to the ester bonds on the side chains of acrylic resins, their heat resistance, wear resistance and chemical resistance are poor, making the adhesion of the cured film less than ideal. UV adhesives for syringes involve a firm bond between the metal needle and the plastic syringe, so higher requirements are placed on the adhesion of the adhesive.

[0004] The preparation of traditional polyurethane uses non-renewable petroleum resources as raw materials, and petroleum-based polyurethane is difficult to degrade, which has a great impact on the environment. Therefore, green, environmentally friendly, degradable and cheap bio-based polyurethane has received widespread attention. Among them, castor oil is the only natural plant oil containing hydroxyl groups. It has the advantages of abundant raw material sources and renewable nature. The long chain in the molecule can improve the water resistance, flexibility and chemical resistance of the cured film. If a bio-based polyurethane can be prepared, it will be of great significance. Summary of the invention

[0005] In order to solve the problems in the prior art, the present invention proposes a castor oil-based polyurethane acrylate prepolymer, a UV adhesive, and a preparation method and application thereof. The purpose of the present invention is to overcome the shortcomings and deficiencies of the commonly used acrylic needle glue in the prior art, that is, poor water resistance and weather resistance, and to provide a castor oil-based polyurethane acrylate prepolymer, which is a bio-based polyurethane. By introducing the prepolymer into the system, the physical and chemical properties of the adhesive can be controlled and regulated. For example, the castor oil-based polyurethane acrylate prepolymer has the advantages of castor oil, acrylate and polyurethane materials, so that the mechanical strength and weather resistance of the adhesive are greatly improved. The UV adhesive of the present invention has good adhesive adhesion, small volume shrinkage, good heat resistance, water resistance and chemical resistance, and has the advantages of cheap and easy-to-obtain raw materials, green and environmentally friendly, etc., and can be used in the bonding system for light-cured acrylic medical needles.

[0006] One of the objects of the present invention is to provide a castor oil-based polyurethane acrylate prepolymer, preferably,

[0007] The castor oil-based polyurethane acrylate prepolymer comprises at least the following structural formula:

[0008]

[0009] Among them, R 1 Any one selected from the following groups: in The corresponding monomer structure before the reaction is a diisocyanate monomer; wherein the structural formula of the diisocyanate monomer is as follows: O=C=NRN=C=O; R is selected from substituted or unsubstituted straight-chain alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl;

[0010] R 2 The structure obtained by removing the H atom from the hydroxyl group in the hydroxy acrylate monomer.

[0011] In the castor oil-based polyurethane acrylate prepolymer of the present invention, preferably,

[0012] R 1 Including but not limited to any one selected from the following groups:

[0013]

[0014] R 2 Including but not limited to any one selected from the following groups:

[0015]

[0016] The present invention directly utilizes castor oil and diisocyanate to react to obtain a terminal isocyanate prepolymer, and then uses a hydroxy acrylate monomer for end-capping to obtain a castor oil-based polyurethane acrylate prepolymer. The steps are simpler, the molecular weight is smaller, the viscosity is lower, and subsequent operations are convenient.

[0017] The second object of the present invention is to provide a method for preparing a castor oil-based polyurethane acrylate prepolymer as described in any one of the objects of the present invention, preferably,

[0018] Under a protective atmosphere, castor oil, diisocyanate monomers, organotin catalysts and polymerization inhibitors are added to a reactor for a primary reaction. After the reaction is completed, hydroxy acrylate is added for a secondary reaction to obtain a castor oil-based polyurethane acrylate prepolymer.

[0019] In the method for preparing the castor oil-based polyurethane acrylate prepolymer of the present invention, preferably,

[0020] The diisocyanate monomers include but are not limited to at least one selected from isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and hexamethylene diisocyanate (HDI); and / or,

[0021] The polymerization inhibitor includes but is not limited to at least one selected from p-tert-butylcatechol, p-hydroxyanisole, and methylhydroquinone; and / or,

[0022] Organotin catalysts include but are not limited to at least one selected from dibutyltin dioctanoate and stannous octoate; and / or,

[0023] The hydroxy acrylate includes, but is not limited to, at least one selected from the group consisting of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0024] In the method for preparing the castor oil-based polyurethane acrylate prepolymer of the present invention, preferably,

[0025] The mass ratio of diisocyanate monomer to castor oil is 0.4 to 1:1; preferably 0.5 to 0.9:1; and / or,

[0026] The mass ratio of the organotin catalyst to the diisocyanate monomer is 0.09% to 1%:1; preferably 0.09% to 0.2%:1; and / or,

[0027] The mass ratio of the polymerization inhibitor to the diisocyanate monomer is 0.25% to 0.6%:1; preferably 0.28% to 0.32%:1; and / or,

[0028] The temperature of the primary reaction is 40 to 70°C; and / or,

[0029] The time of one reaction is 1h to 6h; and / or,

[0030] The molar ratio of the hydroxy acrylate to the molar ratio of the diisocyanate monomer is 1 to 1.1:1; and / or,

[0031] The temperature of the secondary reaction is 40 to 70°C; and / or,

[0032] The secondary reaction time is 2 to 6 hours.

[0033] In the method for preparing the castor oil-based polyurethane acrylate prepolymer of the present invention, preferably,

[0034] The preparation of the prepolymer of the present invention uses castor oil CO and diisocyanate monomers (including isophorone diisocyanate IPDI or toluene diisocyanate TDI, diphenylmethane diisocyanate MDI, hexamethylene diisocyanate HDI) as raw materials, uses dibutyltin dioctanoate or stannous octoate and other organic tin reagents as catalysts, and after obtaining a polyurethane prepolymer containing an -NCO group, hydroxy acrylate is added for reaction to obtain a photocurable castor oil-based polyurethane acrylate prepolymer.

[0035] The third object of the present invention is to provide a UV adhesive, preferably,

[0036] The UV adhesive comprises monomers, photoinitiators, prepolymers, coupling agents and additives;

[0037] The prepolymer is selected from the castor oil-based polyurethane acrylate prepolymer described in any one of the purposes of the present invention or the castor oil-based polyurethane acrylate prepolymer described in any one of the purposes of the present invention.

[0038] In the UV adhesive of the present invention, preferably,

[0039] In the UV adhesive, by weight:

[0040]

[0041] In addition to the newly synthesized castor oil-based polyurethane acrylate prepolymer, the present invention also adds a coupling agent to help improve the surface properties of the substrate and enhance the water resistance and chemical resistance of the bonding system; in addition, a multifunctional monomer is newly added to the bonding system preparation example to facilitate rapid curing of the system, form a cross-linked network, and enhance the strength and stability of the bonding system.

[0042] In the UV adhesive of the present invention, preferably,

[0043] The monomer includes but is not limited to at least one selected from acrylic monomers and acrylate monomers;

[0044] Preferably,

[0045] The acrylic monomers include but are not limited to at least one selected from acrylic acid and methacrylic acid; and / or,

[0046] The acrylic acid ester monomers include but are not limited to at least one selected from methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate, hydroxypropyl acrylate, glycidyl acrylate, tripropylene glycol diacrylate, trifluoroethyl methacrylate, methyl cyanoacrylate, ethyl cyanoacrylate, hydroxyethyl cyanoacrylate, hydroxypropyl cyanoacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate;

[0047] Further preferably, the UV adhesive monomers described in the present invention include at least soft acrylic ester monomers and hard acrylic ester monomers; wherein the soft acrylic ester monomers are methyl acrylate, ethyl acrylate, butyl acrylate, etc.; the hard acrylic ester monomers are methacrylates, such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, etc.; wherein, among the monomers, the soft acrylic ester monomers account for 5% to 40% of the total mass of the monomers; and the hard acrylic ester monomers account for 5% to 40% of the total mass of the monomers.

[0048] In the UV adhesive of the present invention, preferably,

[0049] The photoinitiator includes but is not limited to at least one selected from benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether, diphenyl ethanedione and its derivatives, dialkoxy acetophenone, α-hydroxyalkyl phenone, α-amino ketone compounds, benzophenone, and thioxanthone;

[0050] Preferably, the diphenylethanedione derivatives include but are not limited to at least one selected from diethylaminodiphenylethanedione and diphenylethane sulfonate; and / or,

[0051] The α-amino ketone compounds include, but are not limited to, at least one selected from 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone and 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone.

[0052] In the UV adhesive of the present invention, preferably,

[0053] The coupling agent includes but is not limited to silane coupling agents;

[0054] Preferably, the coupling agent includes but is not limited to trialkoxy coupling agents; further preferably, the coupling agent is selected from at least one of silane phenyltrimethoxysilane, phenyltriethoxysilane, γ-mercaptopropyltriethoxysilane, methyltriethoxysilane, and γ-aminopropyltriethoxysilane.

[0055] In the UV adhesive of the present invention, preferably,

[0056] The auxiliary agent is selected from at least one of a self-initiator, a stabilizer, and an inhibitor; preferably,

[0057] The co-initiator is but not limited to at least one selected from the group consisting of isooctyl p-dimethylaminobenzoate, azobisisobutyronitrile, diethanolamine, and triethanolamine; and / or,

[0058] The stabilizer is but not limited to at least one selected from boric acid esters and organic acids; and / or,

[0059] The polymerization inhibitor includes but is not limited to at least one selected from hydroquinone, tert-butylcatechol, p-hydroxyanisole, and benzoquinone;

[0060] Further preferably, the stabilizer is selected from at least one of trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-o-cresyl borate, tri-m-benzyl borate, barbituric acid, salicylic acid, lauric acid, fumaric acid and benzoic acid.

[0061] The fourth object of the present invention is to provide a method for preparing the UV adhesive described in any one of the third objects of the present invention, comprising the following steps:

[0062] The raw materials including monomers, photoinitiators, prepolymers, coupling agents and additives are reacted in a vacuum and in the dark to prepare a UV adhesive;

[0063] In the preparation method of the UV adhesive of the present invention, preferably,

[0064] Firstly, raw materials including monomer, prepolymer, coupling agent, stabilizer and polymerization inhibitor are added and mixed, and then photoinitiator and co-initiator are added to react in the dark under vacuum stirring conditions;

[0065] Preferably,

[0066] The vacuum degree of the reaction under vacuum is -0.1MPa to -0.01MPa; and / or,

[0067] More preferably, the light-proof reaction time is 2-3 hours; the stirring speed is 600-800 rpm; and the light-proof reaction temperature is 20-35°C.

[0068] The fifth object of the present invention is to provide a use of the UV adhesive described in any one of the third objects of the present invention as a medical device adhesive, preferably as a sterile syringe needle adhesive.

[0069] The adhesive system described in the present invention can be used for the production and preparation of disposable sterile syringe needles. Aiming at the requirement of firm bonding of medical needles, such as disposable sterile syringes, the present invention utilizes the characteristics of easy operation, firm bonding and good chemical resistance of the single-component acrylic ester UV curing adhesive system, introduces a prepolymer with an interpenetrating network structure into the system, greatly enhances the wetting effect and chemical bond effect of the adhesive, achieves the effect of rapid curing and increased strength, and effectively improves the performance of the cured product and the use efficiency of the adhesive. After curing, the adhesive has high bonding strength, small volume shrinkage, excellent heat resistance and solvent resistance, and can be used as a needle glue for sterile syringes.

[0070] The endpoints and any values ​​of the scope disclosed in the present invention are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, the endpoint values ​​of each scope, the endpoint values ​​of each scope and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be regarded as specifically disclosed in this article.

[0071] Compared with the prior art, the present invention has at least the following advantages:

[0072] The present invention provides a bio-based modified light-cured acrylate type adhesive system for medical needles with high bonding strength and good weather resistance. The adhesive has good adhesion firmness, small volume shrinkage, good heat resistance, water resistance and chemical resistance, and has the advantages of cheap and readily available raw materials, green and environmental protection, etc. DETAILED DESCRIPTION

[0073] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0074] It should also be noted that the various specific technical features described in the following specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0075] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0076] In the present invention, conventional methods in the prior art can be used to confirm the structural units in the copolymer, such as infrared spectroscopy and the amount of monomers added during the polymerization process.

[0077] The present invention will be described in detail below by way of examples. All reagents used are commercially available. Room temperature refers to 25°C.

[0078] All kinds of acrylic acid, acrylate monomers and their synthetic reagents were purchased from Inotech Company.

[0079] Castor oil was purchased from Aladdin.

[0080] Preparation Example 1

[0081] Under a nitrogen atmosphere, 28 g of castor oil CO (hydrogenated castor oil), 20 g of isophorone diisocyanate IPDI, 0.02 g of dibutyltin dioctanoate DBTDL and 0.06 g of tert-butylcatechol TBC were added to a reactor, mechanical stirring was started, the speed was 500 rpm, the temperature was slowly raised to 60° C., and after reacting for 6 hours, 10.5 g of hydroxyethyl acrylate was added at the same temperature and reacted for 4 hours to obtain a castor oil-based polyurethane acrylate prepolymer 1.

[0082] Preparation Example 2

[0083] Under a nitrogen atmosphere, 28 g of castor oil CO, 15.7 g of toluene diisocyanate TDI, 0.015 g of stannous octoate and 0.047 g of tert-butylcatechol TBC were added to a reactor, mechanical stirring was started at a speed of 500 rpm, the temperature was slowly raised to 60°C, and after reacting for 6 hours, 10.5 g of hydroxyethyl acrylate was added at the same temperature and reacted for 4 hours to obtain castor oil-based polyurethane acrylate prepolymer 2.

[0084] Preparation Example 3

[0085] Under a nitrogen atmosphere, 28 g of castor oil CO, 22.5 g of diphenylmethane diisocyanate MDI, 0.023 g of dibutyltin dioctanoate DBTDL and 0.068 g of tert-butylcatechol TBC were added to a reactor, mechanical stirring was started at a speed of 500 rpm, the temperature was slowly raised to 60°C, and after reacting for 6 hours, 10.5 g of hydroxyethyl acrylate was added at the same temperature and reacted for 4 hours to obtain prepolymer 3.

[0086] Preparation Example 4

[0087] Under a nitrogen atmosphere, 28 g of castor oil CO, 15.1 g of hexamethylene diisocyanate HDI, 0.015 g of stannous octoate and 0.045 g of tert-butylcatechol TBC were added to a reactor, mechanical stirring was started, the speed was 500 rpm, the temperature was slowly raised to 60°C, and after reacting for 6 hours, 10.5 g of hydroxyethyl acrylate was added at the same temperature and reacted for 4 hours to obtain castor oil-based polyurethane acrylate prepolymer 4.

[0088] Preparation Example 5

[0089] The formula of Preparation Example 1 was used, except that hydroxyethyl acrylate was replaced by hydroxypropyl acrylate in an equal molar amount in the formula; castor oil-based polyurethane acrylate prepolymer 5 was obtained by the same preparation method.

[0090] Preparation Example 6

[0091] The formula of Preparation Example 1 was used, except that hydroxyethyl methacrylate was replaced with an equal molar amount of hydroxyethyl methacrylate in the formula; castor oil-based polyurethane acrylate prepolymer 6 was obtained by the same preparation method.

[0092] Preparation Example 7

[0093] The formula of Preparation Example 1 was used, except that hydroxyethyl acrylate was replaced by hydroxypropyl methacrylate in an equal molar amount in the formula; castor oil-based polyurethane acrylate prepolymer 7 was obtained by the same preparation method.

[0094] Example 1

[0095] 100 parts of acrylate functional monomers (including 50 parts of ethyl methacrylate EMA, 14 parts of acrylic acid AA, 18 parts of butyl acrylate BA, 11 parts of hydroxypropyl acrylate HPA, and 7 parts of tripropylene glycol diacrylate TPGDA), 30 parts of castor oil-based polyurethane acrylate prepolymer 1, 3 parts of coupling agent methyltriethoxysilane, 1 part of stabilizer triisopropyl borate, and 1 part of inhibitor benzoquinone are mixed in a reactor, and mixed at a speed of 300 rpm for 30 minutes until uniform, and then 3 parts of photoinitiator diphenylethylenedione and 2 parts of co-initiator triethanolamine are added, the vacuum degree is maintained at -0.02 MPa, the speed is 600 rpm, and mechanical stirring is performed in the dark for 3 hours until uniform, to obtain a medical needle adhesive sample 1.

[0096] Example 2

[0097] 100 parts of acrylate functional monomers (including 51 parts of ethyl methacrylate EMA, 8 parts of acrylic acid AA, 16 parts of isooctyl acrylate 2-EHA, 14 parts of hydroxypropyl methacrylate HPMA, 6 parts of methyl cyanoacrylate MCA, and 5 parts of trimethylolpropane triacrylate TMPTA), 30 parts of castor oil-based polyurethane acrylate prepolymer 2, 1 part of coupling agent methyltriethoxysilane, 2 parts of stabilizer triethyl borate, and 1 part of inhibitor hydroquinone are mixed in a reactor, and mixed at a speed of 300 rpm for 30 minutes until uniform, and then 3 parts of photoinitiator benzoin ethyl ether and 2 parts of co-initiator azobisisobutyronitrile are added, the vacuum degree is maintained at -0.03 MPa, the speed is 700 rpm, and mechanical stirring is carried out in the dark for 2 hours until uniform, to obtain a medical needle adhesive sample 2.

[0098] Example 3

[0099] 100 parts of acrylate functional monomers (including 54 parts of butyl methacrylate BMA, 8 parts of methacrylate MAA, 19 parts of glycidyl acrylate GA, 14 parts of hydroxypropyl acrylate HPA, and 5 parts of tripropylene glycol diacrylate TPGDA), 25 parts of castor oil-based polyurethane acrylate prepolymer 3, 3 parts of coupling agent γ-mercaptopropyl triethoxysilane, 1 part of stabilizer tri-n-propyl borate, and 2 parts of inhibitor p-hydroxyanisole are mixed in a reactor, and mixed at a speed of 300 rpm for 30 minutes until uniform, and then 3 parts of photoinitiator benzoin butyl ether and 2 parts of co-initiator diethanolamine are added, the vacuum degree is maintained at -0.02 MPa, the speed is 800 rpm, and mechanical stirring is performed in the dark for 2 hours until uniform, to obtain a medical needle adhesive sample 3.

[0100] Example 4

[0101] 100 parts of acrylate functional monomers (including 50 parts of methyl methacrylate MMA, 11 parts of methacrylate MAA, 15 parts of butyl acrylate BA, 13 parts of hydroxyethyl methacrylate HEMA, 6 parts of trifluoroethyl methacrylate TFEMA, and 5 parts of pentaerythritol triacrylate PETA), 25 parts of castor oil-based polyurethane acrylate prepolymer 4, 3 parts of coupling agent phenyltrimethoxysilane, 1 part of stabilizer trimethyl borate, and 1 part of inhibitor tert-butyl catechol are added into a reactor, mixed at a speed of 300 rpm for 30 minutes until uniform, then 3 parts of photoinitiator benzoin methyl ether and 1 part of co-initiator dimethylaminobenzoic acid isooctyl ester are added, the vacuum degree is maintained at -0.02 MPa, the speed is 600 rpm, and mechanical stirring is performed in the dark for 2 hours until uniform, to obtain a medical needle adhesive sample 4.

[0102] Example 5

[0103] 100 parts of acrylate functional monomers (including 48 parts of methyl methacrylate MMA, 12 parts of methacrylate MAA, 19 parts of isooctyl acrylate 2-EHA, 11 parts of hydroxypropyl methacrylate HPMA, 5 parts of ethyl cyanoacrylate ECA, and 5 parts of pentaerythritol tetraacrylate PETTA), 30 parts of castor oil-based polyurethane acrylate prepolymer 1, 2 parts of coupling agent γ-aminopropyl triethoxysilane, 2 parts of stabilizer barbituric acid, and 1 part of inhibitor tert-butyl catechol are mixed in a reactor, and mixed at a speed of 300 rpm for 30 minutes until uniform, and then 3 parts of photoinitiator dialkoxyacetophenone and 2 parts of auxiliary initiator dimethylaminobenzoic acid isooctyl ester are added, the vacuum degree is maintained at -0.01 MPa, the speed is 700 rpm, and mechanical stirring is carried out in the dark for 3 hours until uniform, to obtain a medical needle adhesive sample 5.

[0104] Example 6

[0105] 100 parts of acrylate functional monomers (including 54 parts of butyl methacrylate BMA, 10 parts of acrylic acid AA, 12 parts of glycidyl acrylate GA, 10 parts of hydroxyethyl methacrylate HEMA, 8 parts of trifluoroethyl methacrylate TFEMA, and 6 parts of pentaerythritol triacrylate PETA), 40 parts of castor oil-based polyurethane acrylate prepolymer 2, 3 parts of coupling agent phenyltrimethoxysilane, 1 part of stabilizer lauric acid, and 1 part of inhibitor hydroquinone are mixed in a reactor, and mixed at a speed of 300 rpm for 30 minutes until uniform, and then 2 parts of photoinitiator α-hydroxyalkyl phenone and 2 parts of co-initiator azobisisobutyronitrile are added, the vacuum degree is maintained at -0.03 MPa, the speed is 800 rpm, and mechanical stirring is carried out in the dark for 3 hours until uniform, to obtain medical needle adhesive sample 6.

[0106] Example 7

[0107] The formula of Example 1 was used, except that castor oil-based polyurethane acrylate prepolymer 2 was used in the formula, and the mixture was mixed and stirred in the same preparation manner until uniform.

[0108] Example 8

[0109] The formula of Example 1 was used, except that castor oil-based polyurethane acrylate prepolymer 3 was used in the formula, and the mixture was mixed and stirred in the same preparation manner until uniform.

[0110] Example 9

[0111] The formula of Example 1 was used, except that castor oil-based polyurethane acrylate prepolymer 4 was used in the formula, and the mixture was mixed and stirred in the same preparation manner until uniform.

[0112] Example 10

[0113] The formula of Example 1 was used, except that castor oil-based polyurethane acrylate prepolymer 5 was used in the formula, and the mixture was mixed and stirred in the same preparation manner until uniform.

[0114] Embodiment 11

[0115] The formula of Example 1 was used, except that castor oil-based polyurethane acrylate prepolymer 6 was used in the formula, and the mixture was mixed and stirred in the same preparation manner until uniform.

[0116] Example 12

[0117] The formula of Example 1 was used, except that castor oil-based polyurethane acrylate prepolymer 7 was used in the formula, and the mixture was mixed and stirred in the same preparation manner until uniform.

[0118] Comparative Example 1

[0119] The formula of Example 1 was used, except that the prepolymer used in the formula was Changxing 6146-100, and the mixture was mixed and stirred in the same preparation method until uniform.

[0120] Comparative Example 2

[0121] The formulation and preparation method of Example 1 are used, except that no coupling agent is added to the formulation, and the mixture is mixed and stirred in the same preparation manner until uniform.

[0122] Comparative Example 3

[0123] The formula and preparation method of Example 1 are used, except that castor oil-based polyurethane acrylate prepolymer 1 is not added to the formula, and the mixture is mixed and stirred in the same preparation manner until uniform.

[0124] Performance Test:

[0125] The needle bonding systems described in Examples 1-6 and Comparative Example 1 were tested as follows:

[0126] (1) Viscosity test method: Brookfield-RVT dial type rotational viscometer, test temperature 25°C, 20 rpm.

[0127] (2) Tensile bond strength test: refer to ASTM D1623 test method.

[0128] (3) Linear curing shrinkage test: Refer to the ISO 2577 test method to measure the change in length of a fixed length of film before and after curing. The shrinkage is obtained by dividing the reduced value by the original value.

[0129] (4) Adhesion: Refer to GB / T 9286-1998 test method, the results are divided into 0-5 levels, 0 is the best and 5 is the worst.

[0130] (5) Water absorption test: Prepare a PU film with a dry film thickness of 60 μm and place it in an oven at 100°C for 1 day. After drying, PU film is completely immersed in water for 24 h. After being taken out, the surface moisture is absorbed and the mass difference before and after water absorption is calculated and divided by the original mass to obtain the water absorption rate.

[0131] (6) Resistance to hydrolysis under wet and hot conditions: The adhesive system was applied to two rubber strips that had been surface-polished and pre-treated, and then bonded after UV curing for 30 seconds. After being placed at room temperature for 2 days, the adhesive was hung in a constant temperature and humidity chamber, loaded with a 1 kg weight, maintained at 95% humidity and 70°C. The time it took for the two rubber strips to be completely peeled off was monitored.

[0132] (7) Chemical resistance: Prepare a film with a dry film thickness of 60 μm, place it in an oven at 100°C for 1 day, soak it in 50% ethanol solution for 12 h, and observe whether the film turns white, softens, or becomes sticky. If it turns white, softens, or becomes sticky, it is abnormal.

[0133] The above tests were repeated three times and the average value was taken. The measurement results are shown in the following table.

[0134] Some performance parameters of each embodiment and comparative example

[0135]

[0136]

[0137] As can be seen from the above table, the viscosity, tensile bonding strength, linear curing shrinkage, adhesion, water absorption, resistance to wet and hot hydrolysis, and chemical resistance parameters of each embodiment are different, which is mainly related to the acrylate monomer formula, prepolymer type and content in each system; compared with the comparative example, only the example after adding the specific prepolymer of the present invention can show greater bonding strength, lower linear curing shrinkage, and better adhesion effect. This is mainly because the strong polar groups such as urethane bonds in the castor oil-based polyurethane acrylate prepolymer of the present invention can form hydrogen bonds with active hydrogen-containing compounds, thereby enhancing the intramolecular force and making the bonding stronger, and the unreacted acrylate structure can continue to react with the acrylate monomer to form a cross-linked network structure, thereby having higher strength, better stability, and better adhesion effect. At the same time, the linear curing shrinkage and water absorption of the adhesive of the embodiment of the present invention are lower, and the resistance to moisture and heat hydrolysis and chemical resistance are better. This is also due to the performance of the castor oil-based polyurethane acrylate prepolymer itself. The addition of the prepolymer and the formation of the network structure greatly increase the density of the bonding system, so that the linear curing shrinkage and water absorption are reduced. The addition of the coupling agent can improve the surface performance of the substrate and improve the water resistance and chemical resistance of the bonding system.

[0138] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0139] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.

[0140] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.

[0141] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.

Claims

1. A castor oil-based polyurethane acrylate prepolymer, It is characterized in that The castor oil-based polyurethane acrylate prepolymer comprises at least the following structural formula: Among them, R 1 Any one selected from the following groups: in The corresponding monomer structure before the reaction is a diisocyanate monomer; R is selected from substituted or unsubstituted straight-chain alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl; R 2 The structure obtained by removing the H atom from the hydroxyl group in the hydroxy acrylate monomer.

2. The castor oil-based polyurethane acrylate prepolymer according to claim 1, Features: R 1 Any one selected from the following groups: R 2 Any one selected from the following groups:

3. A method for preparing the castor oil-based polyurethane acrylate prepolymer according to any one of claims 1 to 2, Features: Under a protective atmosphere, castor oil, diisocyanate monomers, organotin catalysts and polymerization inhibitors are added to a reactor for a primary reaction. After the reaction is completed, hydroxy acrylate is added for a secondary reaction to obtain a castor oil-based polyurethane acrylate prepolymer.

4. The method for preparing the castor oil-based polyurethane acrylate prepolymer according to claim 3, Features: The diisocyanate monomer is at least one selected from isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate; and / or, The polymerization inhibitor is selected from at least one of p-tert-butylcatechol, p-hydroxyanisole and methylhydroquinone; and / or, The organotin catalyst is selected from at least one of dibutyltin dioctanoate and stannous octoate; and / or, The hydroxyacrylate is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

5. The method for preparing the castor oil-based polyurethane acrylate prepolymer according to claim 3, Features: The mass ratio of diisocyanate monomer to castor oil is 0.4 to 1:1; preferably 0.5 to 0.9:1; and / or, The mass ratio of the organotin catalyst to the diisocyanate monomer is 0.09% to 1%:1; preferably 0.09% to 0.2%:1; and / or, The mass ratio of the polymerization inhibitor to the diisocyanate monomer is 0.25% to 0.6%:1; preferably 0.28% to 0.32%:1; and / or, The temperature of the primary reaction is 40 to 70°C; and / or, The time of one reaction is 1 to 6 hours; and / or, The molar ratio of the hydroxy acrylate to the molar ratio of the diisocyanate monomer is 1 to 1.1:1; and / or, The temperature of the secondary reaction is 40 to 70°C; and / or, The secondary reaction time is 2 to 6 hours.

6. A UV adhesive, Features: The UV adhesive comprises monomers, photoinitiators, prepolymers, coupling agents and additives; The prepolymer is selected from the castor oil-based polyurethane acrylate prepolymer according to any one of claims 1-2 or the castor oil-based polyurethane acrylate prepolymer according to any one of claims 3-5.

7. The UV adhesive according to claim 6, Features: In the UV adhesive, by weight: Preferably, 2-3 parts of photoinitiator; and / or, 2-3 parts of coupling agent.

8. The UV adhesive according to claim 6, Features: The monomer is selected from at least one of acrylic acid monomers and acrylate monomers; Preferably, The acrylic monomer is selected from at least one of acrylic acid and methacrylic acid; and / or, The acrylic acid ester monomer is selected from at least one of methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate, hydroxypropyl acrylate, glycidyl acrylate, tripropylene glycol diacrylate, trifluoroethyl methacrylate, methyl cyanoacrylate, ethyl cyanoacrylate, hydroxyethyl cyanoacrylate, hydroxypropyl cyanoacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate and pentaerythritol tetraacrylate.

9. The UV adhesive according to claim 6, Features: The photoinitiator is selected from at least one of benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether, diphenyl ethanedione and its derivatives, dialkoxy acetophenone, α-hydroxyalkyl phenone, α-amino ketone compounds, benzophenone, and thioxanthone; Preferably, the diphenylethanedione derivative is selected from at least one of diethylaminodiphenylethanedione and diphenylethane sulfonate; and / or, The α-amino ketone compound is selected from at least one of 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone and 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone.

10. The UV adhesive according to claim 6, Features: The coupling agent is selected from silane coupling agents; Preferably, the coupling agent is selected from trialkoxy coupling agents; further preferably, the coupling agent is selected from at least one of silane phenyltrimethoxysilane, phenyltriethoxysilane, γ-mercaptopropyltriethoxysilane, methyltriethoxysilane, and γ-aminopropyltriethoxysilane.

11. The UV adhesive according to claim 6, Features: The auxiliary agent is selected from at least one of a self-initiator, a stabilizer, and an inhibitor; preferably, The auxiliary initiator is selected from at least one of isooctyl p-dimethylaminobenzoate, azobisisobutyronitrile, diethanolamine and triethanolamine; and / or, The stabilizer is selected from at least one of boric acid ester and organic acid; and / or, The polymerization inhibitor is selected from at least one of hydroquinone, tert-butylcatechol, p-hydroxyanisole and benzoquinone; Further preferably, the stabilizer is selected from at least one of trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-o-cresyl borate, tri-m-benzyl borate, barbituric acid, salicylic acid, lauric acid, fumaric acid and benzoic acid.

12. A method for preparing the UV adhesive according to any one of claims 6 to 11, It is characterized in that The following steps are involved: Raw materials including monomers, photoinitiators, prepolymers, coupling agents and auxiliary agents are reacted in a vacuum and in the dark to prepare UV adhesive.

13. The method for preparing the UV adhesive according to claim 12, Features: Firstly, raw materials including monomer, prepolymer, coupling agent, stabilizer and polymerization inhibitor are added and mixed, and then photoinitiator and co-initiator are added to react in the dark under vacuum stirring conditions; Preferably, The vacuum degree of the reaction under vacuum is -0.1MPa to -0.01MPa; and / or, More preferably, the light-proof reaction time is 2-3 hours; the stirring speed is 600-800 rpm; and the light-proof reaction temperature is 20-35°C.

14. Use of the UV adhesive according to any one of claims 6 to 11 as a bonding adhesive for medical devices, preferably as a bonding adhesive for sterile syringe needles.

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