CN113773787B - Flame-retardant bi-component polyurethane adhesive for fixing electronic components and preparation method thereof - Google Patents

Abstract

The application relates to the field of double-component polyurethane adhesive, in particular to flame-retardant double-component polyurethane adhesive for fixing electronic components and a preparation method thereof. The application provides a two-component polyurethane adhesive which comprises an A component and a B component, wherein: the component A comprises the following components in percentage by mass: 10 to 20 percent of hydroxyl-terminated hydrogenated polybutadiene, 10 to 20 percent of hydroxyl-terminated polybutadiene-acrylonitrile, 4 to 8 percent of bisphenol A polyether polyol, 2 to 6 percent of dipropylene glycol, 10 to 20 percent of phosphate plasticizer, 0.2 to 0.4 percent of light stabilizer, 0.1 to 0.3 percent of ultraviolet absorbent, 0.2 to 0.4 percent of antioxidant, 35 to 45 percent of aluminum hydroxide, 3 to 6 percent of 3A molecular sieve activated powder and 0.1 to 0.2 percent of catalyst; the component B comprises the following components: 30 to 45 percent of isocyanate end-capped polyurethane prepolymer, 10 to 15 percent of polyphenyl polymethylene polyisocyanate, 10 to 15 percent of phosphate plasticizer, 0.3 to 0.6 percent of silane coupling agent and 30 to 45 percent of aluminum hydroxide.

Description

Flame-retardant bi-component polyurethane adhesive for fixing electronic components and preparation method thereof

Technical Field

The application relates to the field of double-component polyurethane adhesive, in particular to flame-retardant double-component polyurethane adhesive for fixing electronic components and a preparation method thereof.

Background

At present, most of traditional single-component organic silicon sealant is used for fixing electronic components, and the components and the Printed Circuit Board (PCB) surface are fixed in an auxiliary mode through moisture curing, so that the effects of damping and reinforcing are achieved, and the failure of welding spots of the components caused by vibration drop is reduced. Along with the rapid development of new energy automobiles, electronic circuit boards for vehicle-mounted PCBs and power battery PCBs are more and more, the requirements on the shock resistance strength of component fixation are higher, the strength and the shock absorption effect of the traditional organic silicon sealant cannot meet the requirements, meanwhile, the service life of the automobile is long, the potential precipitation pollution risk of silicone oil is focused, the curing speed of a single-component organic silicon sealant system is slow, the positioning time is long, and the production efficiency is influenced.

The polyurethane has the characteristics of high strength and high toughness, and has obvious advantages when being applied to the fixation of vehicle-mounted electronic components. However, the diversity of PCB materials and electronic components requires the polyurethane adhesive to meet the universality, and in addition, the fixation of the electronic components accords with UL 94V-0 level flame retardant test, meets the environmental protection requirements of REACH and RoHS, and can be used in the temperature range of-50 ℃ to 125 ℃ for a long time without failure. Conventional polyurethane adhesives fail to meet the above requirements. Therefore, it is necessary to provide a polyurethane adhesive which meets the flame-retardant test and is resistant to high and low temperatures.

Disclosure of Invention

The embodiment of the application provides a flame-retardant type bi-component polyurethane adhesive for fixing electronic components, which not only meets the requirements of UL 94V-0 level flame retardance test, REACH and RoHS environmental protection, but also can be used in the temperature range of-50 ℃ to 125 ℃ for a long time.

In a first aspect, the present application provides a flame retardant two-component polyurethane adhesive for fixing electronic components, comprising an a component and a B component, wherein:

the component A comprises the following components in percentage by mass: 10 to 20 percent of hydroxyl-terminated hydrogenated polybutadiene, 10 to 20 percent of hydroxyl-terminated polybutadiene-acrylonitrile, 4 to 8 percent of bisphenol A polyether polyol, 2 to 6 percent of dipropylene glycol, 10 to 20 percent of phosphate plasticizer, 0.2 to 0.4 percent of light stabilizer, 0.1 to 0.3 percent of ultraviolet absorbent, 0.2 to 0.4 percent of antioxidant, 35 to 45 percent of aluminum hydroxide, 3 to 6 percent of 3A molecular sieve activated powder and 0.1 to 0.2 percent of catalyst;

the component B comprises the following components in percentage by mass: 30 to 45 percent of isocyanate end-capped polyurethane prepolymer, 10 to 15 percent of polyphenyl polymethylene polyisocyanate, 10 to 15 percent of phosphate plasticizer, 0.3 to 0.6 percent of silane coupling agent and 30 to 45 percent of aluminum hydroxide.

In some embodiments, the hydroxyl-terminated hydrogenated polybutadiene in the A-component is prepared by catalytic hydrogenation of a hydroxyl-terminated polybutadiene having a hydroxyl number of 31.5mgKOH/g to 60mgKOH/g.

In some embodiments, the hydroxyl-terminated polybutadiene-acrylonitrile in the A component is obtained by copolymerizing polybutadiene and acrylonitrile, and the mass content of the acrylonitrile in the hydroxyl-terminated polybutadiene-acrylonitrile is 5-15%.

In some embodiments, the bisphenol A polyether polyol in the A component is prepared from bisphenol A and propylene oxide and has a hydroxyl value of 220mgKOH/g to 350mgKOH/g.

In some embodiments, the phosphate plasticizer in the a-component is one or a mixture of two of isopropylated triphenyl phosphate (IPPP), cresyl Diphenyl Phosphate (CDP).

In some embodiments, the light stabilizer in the A component is a hindered amine light stabilizer. In some of the preferred embodiments of the present invention, the hindered amine light stabilizer is a mixture of bis (1, 2, 6-pentamethyl-4-piperidine) sebacate and 1-methyl-8- (1, 2, 6-pentamethyl-4-piperidine) sebacate any one of poly (4-hydroxy-2, 6-tetramethyl-1-piperidineethanol) succinate.

In some embodiments, the ultraviolet absorber in the A component is benzotriazole ultraviolet absorber. In some preferred embodiments, the benzotriazole-based ultraviolet absorber is any of 2'- (2' -hydroxy-3 '-tert-butyl-5' -methylphenyl) -5-chlorobenzotriazole, 2- [ 2-hydroxy-3, 5-bis (1, 1-dimethylpropylphenyl) ] -2H-benzotriazole, 2- (2H-benzotriazol-2-yl) -6-dodecyl-4-cresol.

In some embodiments, the antioxidant in the A component is a hindered phenol antioxidant. In some preferred embodiments, the hindered phenolic antioxidant is any one of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], n-stearyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, isooctyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

In some embodiments, the catalyst in the A component is an organobismuth catalyst. In some preferred embodiments, the organobismuth based catalyst is bismuth isooctanoate.

In some embodiments, the isocyanate-terminated polyurethane prepolymer in the component B is obtained by reacting liquefied MDI, hydroxyl-terminated hydrogenated polybutadiene and a phosphate plasticizer, and the mass content of NCO in the isocyanate-terminated polyurethane prepolymer is 8.0-12.0%; wherein the phosphate plasticizer used for preparing the isocyanate-terminated polyurethane prepolymer is any one or a mixture of two of isopropyl triphenyl phosphate (IPPP) and resorcinol bis (diphenyl phosphate) (RDP).

In some embodiments, the phosphate plasticizer in the B component is any one or a mixture of two of isopropylated triphenyl phosphate (IPPP), resorcinol bis (diphenyl phosphate) (RDP).

In some embodiments, the silane coupling agent in the component B is an epoxy silane coupling agent.

In a second aspect, the present application further provides a method for preparing the flame retardant type two-component polyurethane adhesive for fixing electronic components, which includes the following steps:

preparing a component A: adding hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, bisphenol A polyether polyol, dipropylene glycol, phosphate plasticizer, light stabilizer, ultraviolet absorbent and antioxidant into a stirrer for dispersing for 10min under the conditions that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding pre-dried aluminum hydroxide powder and 3A molecular sieve activated powder, dispersing for 15min under the conditions that the vacuum degree is lower than-0.095 MPa, adding a catalyst after nitrogen decompression, dispersing for 10min under the conditions that the vacuum degree is lower than-0.095 MPa, and discharging to obtain a component A;

and (3) preparing a component B: adding isocyanate terminated polyurethane prepolymer, polyphenyl polymethylene polyisocyanate, phosphate plasticizer and silane coupling agent into a stirrer to disperse for 10min under the condition that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding aluminum hydroxide powder, dispersing for 15min under the condition that the vacuum degree is lower than-0.095 MPa, and discharging to obtain a component B;

mixing: and mixing the component A and the component B according to the volume ratio of 1:1 to obtain the double-component polyurethane adhesive.

The double-component polyurethane adhesive can be used for auxiliary fixing and bonding of electronic components on a Printed Circuit Board (PCB), and the occurrence of component deformation and falling phenomena caused by vibration and the like is reduced.

According to the preparation method, the hydroxyl-terminated hydrogenated polybutadiene and the hydroxyl-terminated polybutadiene-acrylonitrile are introduced into the polyurethane material, so that the wide adhesion of metal and nonmetal materials can be realized, and meanwhile, the high and low temperature resistance of the polyurethane is further improved by adding the hindered amine light stabilizer, the ultraviolet absorber and the hindered phenol antioxidant; the flame retardant effect is realized through the compound collocation of the phosphate plasticizer and the aluminum hydroxide; compared with the traditional organotin catalyst, the organobismuth catalyst is used as a curing speed regulator, and the heat resistance of the polyurethane adhesive is obviously improved.

The beneficial effects that technical scheme that this application provided brought include: the application of the polyurethane adhesive in the temperature range of-50 ℃ to 125 ℃ is realized through the selection and collocation of the heat-resistant resin and the auxiliary agent, the flame retardant level of the polyurethane adhesive reaches UL V-0 level, and the polyurethane adhesive has excellent adhesion matching property on base materials of circuit boards and components, such as aluminum, PC materials, ABS materials, PET materials and the like.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic flow chart of a preparation method of a flame retardant type two-component polyurethane adhesive for fixing electronic components according to an embodiment of the present application.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

The embodiment of the application provides a flame-retardant type bi-component polyurethane adhesive for fixing electronic components, which can solve the problem that the existing polyurethane adhesive can not meet the bonding matching performance of various base materials.

The embodiment of the application provides a fire-retardant bi-component polyurethane adhesive for fixing electronic components, which comprises an A component and a B component, wherein:

the component A comprises the following components in percentage by mass: 10 to 20 percent of hydroxyl-terminated hydrogenated polybutadiene, 10 to 20 percent of hydroxyl-terminated polybutadiene-acrylonitrile (HTBN), 4 to 8 percent of bisphenol A polyether polyol, 2 to 6 percent of dipropylene glycol, 10 to 20 percent of phosphate plasticizer, 0.2 to 0.4 percent of light stabilizer, 0.1 to 0.3 percent of ultraviolet absorbent, 0.2 to 0.4 percent of antioxidant, 35 to 45 percent of aluminum hydroxide, 3 to 6 percent of 3A molecular sieve activated powder and 0.1 to 0.2 percent of catalyst;

the component B comprises the following components in percentage by mass: 30 to 45 percent of isocyanate terminated polyurethane prepolymer, 10 to 15 percent of polyphenyl polymethylene polyisocyanate (PAPI), 10 to 15 percent of phosphate plasticizer, 0.3 to 0.6 percent of silane coupling agent and 30 to 45 percent of aluminum hydroxide.

The component A comprises the following components: the hydroxyl-terminated hydrogenated polybutadiene is prepared by catalytic hydrogenation of hydroxyl-terminated polybutadiene, and the hydroxyl value of the hydroxyl-terminated polybutadiene is 31.5 mgKOH/g-60 mgKOH/g; the hydroxyl-terminated polybutadiene-acrylonitrile is obtained by copolymerizing polybutadiene and acrylonitrile, and the mass content of the acrylonitrile in the hydroxyl-terminated polybutadiene-acrylonitrile is 5% -15%; bisphenol A polyether polyol is prepared from bisphenol A and propylene oxide, and has a hydroxyl value of 220 mgKOH/g-350 mgKOH/g; the phosphate plasticizer is one or two of isopropyl triphenyl phosphate (IPPP) and Cresyl Diphenyl Phosphate (CDP); the light stabilizer is selected from hindered amine light stabilizer, the hindered amine light stabilizer is a mixture of bis (1, 2, 6-pentamethyl-4-piperidine) sebacate and 1-methyl-8- (1, 2, 6-pentamethyl-4-piperidine) sebacate any one of poly (4-hydroxy-2, 6-tetramethyl-1-piperidineethanol) succinate; the ultraviolet absorbent is selected from benzotriazole ultraviolet absorbent which is any one of 2'- (2' -hydroxy-3 '-tertiary butyl-5' -methylphenyl) -5-chlorobenzotriazole, 2- [ 2-hydroxy-3, 5-di (1, 1-dimethylpropylphenyl) ] -2H-benzotriazole and 2- (2H-benzotriazole-2-yl) -6-dodecyl-4-cresol; the antioxidant is selected from hindered phenol antioxidants, wherein the hindered phenol antioxidants are any one of pentaerythritol tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], n-stearyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate and isooctyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate; the catalyst is selected from organic bismuth catalysts, and the organic bismuth catalysts are bismuth isooctanoate.

The component B comprises the following components: the isocyanate-terminated polyurethane prepolymer is obtained by reacting liquefied MDI, hydroxyl-terminated hydrogenated polybutadiene and phosphate plasticizer, and the mass content of NCO in the isocyanate-terminated polyurethane prepolymer is 8.0% -12.0%; the phosphate plasticizer is any one or a mixture of two of isopropyl triphenyl phosphate (IPPP) and resorcinol bis (diphenyl phosphate) (RDP); the silane coupling agent is epoxy silane coupling agent.

The preparation process of the isocyanate terminated polyurethane prepolymer in the component B comprises the following steps: vacuum dehydrating hydroxyl-terminated hydrogenated polybutadiene at 120 ℃ and a pressure lower than-0.098 MPa until no bubble exists, cooling to below 50 ℃, adding liquefied MDI and a phosphate plasticizer, uniformly mixing, reacting under the protection of dry nitrogen at 70-75 ℃, sampling and testing the NCO content every 30min, and cooling and discharging when the NCO content reaches 8.0wt% -12.0wt% and keeps stable; the phosphate plasticizer used in the preparation process is any one or a mixture of two of isopropylated triphenyl phosphate (IPPP) and resorcinol bis (diphenyl phosphate) (RDP).

Referring to fig. 1, the embodiment of the application also provides a preparation method of the flame-retardant two-component polyurethane adhesive for fixing electronic components, which comprises the following steps:

preparing a component A: weighing 10-20% of hydroxyl-terminated polybutadiene, 10-20% of hydroxyl-terminated polybutadiene-acrylonitrile (HTBN), 4-8% of bisphenol A polyether polyol, 2-6% of dipropylene glycol, 10-20% of phosphate plasticizer, 0.2-0.4% of light stabilizer, 0.1-0.3% of ultraviolet absorbent and 0.2-0.4% of antioxidant under the condition that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, dispersing for 10min, adding 3-6% of 3A molecular sieve activated powder and 35-45% of pre-dried aluminum hydroxide powder, dispersing for 15min under the condition that the vacuum degree is lower than-0.095 MPa, adding 0.1-0.2% of catalyst after nitrogen decompression, dispersing for 10min under the condition that the vacuum degree is lower than-0.095 MPa, discharging, sealing and preserving;

and (3) preparing a component B: weighing 30-45% of isocyanate-terminated polyurethane prepolymer, 10-15% of polyphenyl polymethylene polyisocyanate (PAPI), 10-15% of phosphate plasticizer and 0.3-0.6% of silane coupling agent according to mass percent under the conditions that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding the mixture into a stirrer to disperse for 10min, adding 30-45% of aluminum hydroxide powder, dispersing for 15min under the conditions that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

mixing: and mixing the component A and the component B according to the volume ratio of 1:1 to realize solidification, thus obtaining the double-component polyurethane adhesive.

The flame retardant two-component polyurethane adhesive for fixing electronic components provided in the present application and the preparation method thereof are described in detail below with reference to examples and comparative examples.

The raw material description:

hydroxyl-terminated hydrogenated polybutadiene: HLBH-P2000, available from cray vally Inc.;

liquified MDI: CDMDI-100L, available from Wanhua chemistry;

hydroxyl-terminated polybutadiene-acrylonitrile (HTBN): form II, available from Shandong zilone;

bismuth isooctanoate, biCAT 8124, available from advanced U.S. chemistry;

light stabilizers: tinuvin 292, available from basf;

ultraviolet absorber: tinuvin 571, available from basf;

an antioxidant: irganox 1135, available from Basoff;

bisphenol a polyether polyol: dianol 320, available from saiick;

PAPI isocyanate PM200, available from Wanhua chemistry;

epoxy silane coupling agent A-187, available from Michaelsen;

pretreatment of aluminum hydroxide powder: the method comprises the following steps of: drying at 130-140 deg.C for more than 8 hr, cooling, introducing nitrogen, and sealing for use;

the NCO-terminated polypropylene carbonate polyol prepolymer (hereinafter referred to as PP-1 prepolymer) in the B component was prepared by the following procedure: 450g of hydroxyl-terminated hydrogenated polybutadiene is weighed and added into a four-neck flask, 150g of IPPP plasticizer is added, the mixture is heated to 120 ℃, vacuumizing and dehydrating are carried out under the condition that the vacuum pressure is lower than-0.098 MPa until no bubble is generated, the dehydration is stopped, the temperature is reduced and cooled to below 50 ℃, 400g of liquefied MDI is added, stirring is carried out under the nitrogen protection atmosphere, the reaction is carried out for 1-3h under the condition of 70-75 ℃, the NCO content is measured to be 9.5wt%, the mixture is discharged, and the mixture is filled with nitrogen and sealed for later use.

Example 1:

the embodiment 1 of the application provides a preparation method of flame-retardant bi-component polyurethane adhesive for fixing electronic components, which comprises the following steps:

preparing a component A: weighing 14 parts of hydroxyl-terminated hydrogenated polybutadiene, 14 parts of hydroxyl-terminated polybutadiene-acrylonitrile, 6 parts of bisphenol A polyether polyol, 5 parts of dipropylene glycol, 15 parts of IPPP plasticizer, 0.3 part of light stabilizer tinuvin 292, 0.3 part of ultraviolet absorbent tinuvin 571 and 0.2 part of antioxidant Irganox 1135 under the condition that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding the mixture into a stirrer to disperse for 10 minutes, adding 41.5 parts of aluminum hydroxide powder and 3.5 parts of 3A molecular sieve activated powder, dispersing for 15 minutes under the condition that the vacuum degree is lower than-0.095 MPa, adding 0.2 part of bismuth isooctanoate after nitrogen decompression, dispersing for 10 minutes under the condition that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

and (3) preparing a component B: weighing 35 parts of PP-1 prepolymer, 10 parts of PAPI isocyanate, 13 parts of IPPP plasticizer and 0.4 part of epoxy silane coupling agent according to parts by mass under the conditions that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding the mixture into a stirrer to disperse for 10min, adding 41.6 parts of aluminum hydroxide powder, dispersing for 15min under the conditions that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

mixing: and (3) adding the component A and the component B into a mixer according to the volume ratio of 1:1 at the temperature of 23 ℃ and the relative humidity of 50%, and mixing to obtain the double-component polyurethane adhesive.

Example 2:

the embodiment 2 of the application provides a preparation method of flame-retardant bi-component polyurethane adhesive for fixing electronic components, which comprises the following steps:

preparing a component A: according to parts by mass, under the conditions that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, weighing 10 parts of hydroxyl-terminated polybutadiene, 18 parts of hydroxyl-terminated polybutadiene-acrylonitrile, 6 parts of bisphenol A polyether polyol, 5 parts of dipropylene glycol, 15 parts of IPPP plasticizer, 0.3 part of light stabilizer tinuvin 292, 0.3 part of ultraviolet absorbent tinuvin 571 and 0.2 part of antioxidant Irganox 1135, adding the mixture into a stirrer, dispersing for 10 minutes, adding 41.5 parts of aluminum hydroxide powder and 3.5 parts of 3A molecular sieve activated powder, dispersing for 15 minutes under the condition that the vacuum degree is lower than-0.095 MPa, adding 0.2 part of bismuth isooctanoate after nitrogen decompression, dispersing for 10 minutes under the condition that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

and (3) preparing a component B: the preparation of component B was the same as in example 1;

mixing: and (3) adding the component A and the component B into a mixer according to the volume ratio of 1:1 at the temperature of 23 ℃ and the relative humidity of 50%, and mixing to obtain the double-component polyurethane adhesive.

Comparative example 1:

comparative example 1 of the present application provides a method for preparing a two-component polyurethane gel, comprising the steps of:

preparing a component A: weighing 28 parts of hydroxyl-terminated polybutadiene-acrylonitrile, 6 parts of bisphenol A polyether polyol, 5 parts of dipropylene glycol, 15 parts of IPPP plasticizer, 0.3 part of light stabilizer tinuvin 292, 0.3 part of ultraviolet absorbent tinuvin 571 and 0.2 part of antioxidant Irganox 1135 under the condition that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding into a stirrer to disperse for 10min, then adding 41.5 parts of aluminum hydroxide powder and 3.5 parts of 3A molecular sieve activated powder, dispersing for 15min under the condition that the vacuum degree is lower than-0.095 MPa, adding 0.2 part of bismuth isooctanoate after nitrogen decompression, dispersing for 10min under the condition that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

and (3) preparing a component B: the preparation of component B was the same as in example 1;

mixing: and (3) adding the component A and the component B into a mixer according to the volume ratio of 1:1 at the temperature of 23 ℃ and the relative humidity of 50%, and mixing to obtain the double-component polyurethane adhesive.

Comparative example 2:

comparative example 2 of the present application provides a method for preparing a two-component polyurethane gel, comprising the steps of:

preparing a component A: weighing 14 parts of hydroxyl-terminated polybutadiene, 14 parts of hydroxyl-terminated polybutadiene-acrylonitrile, 6 parts of bisphenol A polyether polyol, 5 parts of dipropylene glycol and 15 parts of IPPP plasticizer under the conditions that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding into a stirrer to disperse for 10min, adding 41.5 parts of aluminum hydroxide powder and 4.3 parts of 3A molecular sieve activated powder, dispersing for 15min under the conditions that the vacuum degree is lower than-0.095 MPa, adding 0.2 part of bismuth isooctanoate after nitrogen decompression, dispersing for 10min under the conditions that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

and (3) preparing a component B: the preparation of component B was the same as in example 1;

mixing: and (3) adding the component A and the component B into a mixer according to the volume ratio of 1:1 at the temperature of 23 ℃ and the relative humidity of 50%, and mixing to obtain the double-component polyurethane adhesive.

Comparative example 3:

comparative example 3 of the present application provides a method for preparing a two-component polyurethane gel, comprising the steps of:

preparing a component A: weighing 14 parts of hydroxyl-terminated hydrogenated polybutadiene, 14 parts of hydroxyl-terminated polybutadiene-acrylonitrile, 6 parts of bisphenol A polyether polyol, 5 parts of dipropylene glycol, 15 parts of IPPP plasticizer, 0.3 part of light stabilizer tinuvin 292, 0.3 part of ultraviolet absorbent tinuvin 571 and 0.2 part of antioxidant Irganox 1135 under the condition that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding the mixture into a stirrer to disperse for 10 minutes, adding 41.5 parts of aluminum hydroxide powder and 3.62 parts of 3A molecular sieve activated powder, dispersing for 15 minutes under the condition that the vacuum degree is lower than-0.095 MPa, adding 0.08 part of dibutyltin dilaurate after nitrogen decompression, dispersing for 10 minutes under the condition that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

and (3) preparing a component B: the preparation of component B was the same as in example 1;

mixing: and (3) adding the component A and the component B into a mixer according to the volume ratio of 1:1 at the temperature of 23 ℃ and the relative humidity of 50%, and mixing to obtain the double-component polyurethane adhesive.

Comparative example 4:

comparative example 4 of the present application provides a method for preparing a two-component polyurethane gel comprising the steps of:

preparing a component A: weighing 14 parts of hydroxyl-terminated polybutadiene, 14 parts of hydroxyl-terminated polybutadiene-acrylonitrile, 7 parts of dipropylene glycol, 15 parts of IPPP plasticizer, 0.3 part of light stabilizer tinuvin 292, 0.3 part of ultraviolet absorbent tinuvin 571 and 0.2 part of antioxidant Irganox 1135 under the condition that the temperature is 5-25 ℃ and the humidity is lower than 50%, adding into a stirrer to disperse for 10min, then adding 43.7 parts of aluminum hydroxide powder and 5.3 parts of 3A molecular sieve activated powder, dispersing for 15min under the condition that the vacuum degree is lower than-0.095 MPa, adding 0.2 part of bismuth isooctanoate after nitrogen decompression, dispersing for 10min under the condition that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

and (3) preparing a component B: the preparation of component B was the same as in example 1;

mixing: and (3) adding the component A and the component B into a mixer according to the volume ratio of 1:1 at the temperature of 23 ℃ and the relative humidity of 50%, and mixing to obtain the double-component polyurethane adhesive.

Comparative example 5:

comparative example 5 of the present application provides a method for preparing a two-component polyurethane gel comprising the steps of:

preparing a component A: weighing 14 parts of hydroxyl-terminated polybutadiene (Poly bd R-45 HT), 14 parts of hydroxyl-terminated polybutadiene-acrylonitrile, 7 parts of dipropylene glycol, 15 parts of IPPP plasticizer, 0.3 part of light stabilizer tinuvin 292, 0.3 part of ultraviolet absorbent tinuvin 571 and 0.2 part of antioxidant Irganox 1135 under the condition that the ambient temperature is 5-25 ℃ and the humidity is lower than 50%, adding into a stirrer to disperse for 10min, then adding 43.7 parts of aluminum hydroxide powder and 5.3 parts of 3A molecular sieve activated powder, dispersing for 15min under the condition that the vacuum degree is lower than-0.095 MPa, adding 0.2 part of bismuth isooctanoate after nitrogen decompression, dispersing for 10min under the condition that the vacuum degree is lower than-0.095 MPa, discharging, and sealing and preserving;

and (3) preparing a component B: the preparation of component B was the same as in example 1;

mixing: and (3) adding the component A and the component B into a mixer according to the volume ratio of 1:1 at the temperature of 23 ℃ and the relative humidity of 50%, and mixing to obtain the double-component polyurethane adhesive.

The two-component polyurethane adhesives prepared in examples 1 to 2 and comparative examples 1 to 5 were subjected to performance tests, specifically:

1. tensile strength and elongation at break: the performance of 3h and 7d were tested according to GB/T528-2009 test, respectively;

2. tensile shear strength: controlling the thickness of the adhesive layer to be 0.2mm according to HG/T4363-2012 test, and curing for 168 hours;

3. initial adhesion: respectively coating double-component polyurethane adhesive on adhesive base materials (green oil circuit board, aluminum plate, PC board, PET film and ABS board) at the temperature of 23 ℃ and relative humidity of 50%, coating adhesive tapes with the length of about 100mm, the width of about 10mm and the thickness of about 5mm, curing for 7 days, using a nipper pliers to perform peeling test, cutting adhesive at intervals of about 2mm, and calculating the cohesive failure rate, wherein the higher the cohesive failure rate is, the better the adhesive performance is, the cohesive failure is represented by CF, and the interfacial failure is represented by AF;

4. cold and hot impact: cycling the bonded sample for 500 times according to the temperature conditions of-50 ℃, 125 ℃, -50 ℃ and … at 125 ℃, setting the time of each temperature point to be 1h, keeping the temperature interval to be not more than 1min, standing for 24h at 25 ℃ after the cycling is finished, and then testing the bonding performance;

5. high temperature resistance test: placing the bonding sample at 125 ℃ for standing for 1000 hours, taking out, and standing at 25 ℃ for 24 hours for bonding performance test;

the specific performance test results of the polyurethane adhesives of examples 1-2 and comparative examples 1-5 are shown in Table 1.

Table 1: results of Performance test of polyurethane gums of examples 1-2 and comparative examples 1-5

Analysis of table 1 shows that: through reasonable collocation of hydroxyl-terminated hydrogenated polybutadiene and hydroxyl-terminated polybutadiene-acrylonitrile, a certain amount of bisphenol A polyether polyol is compatible, so that the adhesion of metal materials such as aluminum, ABS, PC and the like can be realized, meanwhile, the heat resistance of polyurethane can be effectively improved by adopting hydrogenated polybutadiene and compounding with additives such as light stabilizer and the like, as can be seen from the table 1, the heat stability of polyurethane is greatly influenced by organic tin, and the defect of organic tin is avoided by adopting an organic bismuth catalyst.

In the description of the present specification, reference to the terms "one embodiment/manner," "some embodiments/manner," "example," "a particular example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/manner or example is included in at least one embodiment/manner or example of the present application. In this specification, the schematic representations of the above terms are not necessarily for the same embodiment/manner or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/modes or examples described in this specification and the features of the various embodiments/modes or examples can be combined and combined by persons skilled in the art without contradiction.

It should be noted that in this application, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. In the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless explicitly specified otherwise.

The foregoing is merely a specific embodiment of the application to enable one skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. The flame-retardant bi-component polyurethane adhesive for fixing the electronic components is characterized by comprising an A component and a B component, wherein:

the component A comprises the following components in percentage by mass: 10 to 20 percent of hydroxyl-terminated hydrogenated polybutadiene, 10 to 20 percent of hydroxyl-terminated polybutadiene-acrylonitrile, 4 to 8 percent of bisphenol A polyether polyol, 2 to 6 percent of dipropylene glycol, 10 to 20 percent of phosphate plasticizer, 0.2 to 0.4 percent of light stabilizer, 0.1 to 0.3 percent of ultraviolet absorbent, 0.2 to 0.4 percent of antioxidant, 35 to 45 percent of aluminum hydroxide, 3 to 6 percent of 3A molecular sieve activated powder and 0.1 to 0.2 percent of catalyst;

the component B comprises the following components in percentage by mass: 30 to 45 percent of isocyanate end-capped polyurethane prepolymer, 10 to 15 percent of polyphenyl polymethylene polyisocyanate, 10 to 15 percent of phosphate plasticizer, 0.3 to 0.6 percent of silane coupling agent and 30 to 45 percent of aluminum hydroxide;

the light stabilizer in the component A is a hindered amine light stabilizer;

the antioxidant in the component A is a hindered phenol antioxidant;

the catalyst in the component A is an organic bismuth catalyst.

2. The flame-retardant two-component polyurethane adhesive for fixing electronic components according to claim 1, wherein the phosphate plasticizer in the component a is one or a mixture of two of isopropylated triphenyl phosphate and cresyl diphenyl phosphate.

3. The flame retardant two-component polyurethane adhesive for electronic component mounting according to claim 1, wherein the ultraviolet absorber in the component a is benzotriazole ultraviolet absorber.

4. The flame retardant two-component polyurethane adhesive for electronic component mounting according to claim 1, wherein the isocyanate terminated polyurethane prepolymer in the B component is obtained by reacting liquefied MDI, hydroxyl terminated hydrogenated polybutadiene and a phosphate plasticizer.

5. The flame retardant two-component polyurethane adhesive for fixing electronic components according to claim 1, wherein the phosphate plasticizer in the B component is one or a mixture of two of isopropylated triphenyl phosphate and resorcinol bis (diphenyl phosphate).

6. The flame-retardant two-component polyurethane adhesive for fixing electronic components according to claim 1, wherein the silane coupling agent in the component B is an epoxy silane coupling agent.

7. The method for preparing the flame-retardant two-component polyurethane adhesive for fixing electronic components according to any one of claims 1 to 6, comprising the steps of:

preparing a component A: mixing hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, bisphenol A polyether polyol, dipropylene glycol, phosphate plasticizer, light stabilizer, ultraviolet absorbent and antioxidant, adding aluminum hydroxide and 3A molecular sieve activated powder, mixing, adding catalyst, mixing, discharging to obtain component A;

and (3) preparing a component B: mixing isocyanate-terminated polyurethane prepolymer, polyphenyl polymethylene polyisocyanate, phosphate plasticizer and silane coupling agent, and then adding aluminum hydroxide for mixing to obtain a component B;

mixing: and mixing the component A and the component B according to the volume ratio of 1:1 to obtain the double-component polyurethane adhesive.

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