A kind of UV curings heat conduction pressure sensitive adhesive and preparation method thereof
Technical field
The present invention relates to heat-conducting polymer material technical fields, and in particular to a kind of UV curing heat conduction pressure sensitive adhesives and its preparation
Method.
Background technology
Heat Conduction Material is widely used in the every field of electric industry, science and techniques of defence and national economy.Industrial requirement
With the development of science and technology, all kinds of Heat Conduction Materials are proposed with update, higher requirement.In addition to heat conductivility, it is also desirable to material
With preferable comprehensive performance.
The heat generated with the development of microelectronics integrated technology and hollow printed board high density packaging technique, electronic component
The rapid accumulation of amount, will make component remain to reliably work normally, and there is timely and efficient heat-sinking capability, which to become, influences first device
The key factor of part service life.As the heat conduction pressure sensitive adhesive that thermal interfacial material uses, by its good compressible morphotropism
When characteristics are filled between radiator and heat source, heater and radiator can be fixed together, form an entirety, driven
In addition to the presence of low thermal conductivity air so that be in close contact between two interfaces, improve heat dissipation effect.
Patent document CN107057600A discloses a kind of preparation method of water-based acrylic heat conduction pressure sensitive adhesive tape, relies on
The coated with thermally conductive pressure sensitive adhesive above and below glass fabric layer, subsequent technique need to be through room temperature curings for 24 hours, and time-consuming, and operation is more
Trouble.Patent document CN105778845A discloses a kind of preparation method of solvent type heat conduction pressure sensitive adhesive, makes in preparation process
With volatile, toxic reagent, the preparation method is to be improved in the feature of environmental protection and safety etc..Patent document
CN106634724A discloses a kind of acrylate solvent-free pressure-sensitive adhesive and preparation method thereof, is first mixed using solvent dissolving
Glue, then solvent removed by vacuum obtain solvent-free pressure-sensitive adhesive, actually also use solvent in preparation process, it is equally possible to
In the presence of environmental protection and safety problem.
UV solidified pressure-sensitives, because its curing rate is fast, pollution is small, low power consumption and other advantages have the larger market competitiveness,
But UV solidified pressure-sensitives there is also poor thermal conductivity, adhesive property is poor the shortcomings of.
Patent document CN106867433A discloses a kind of preparation method of UV curing heat resistant type pressure sensitive adhesive tape, using containing
The monomer of naphthalene is prepared for UV curing heat resistant type pressure sensitive adhesives as curing agent, extends the use scope of UV pressure sensitive adhesives.It but should
The research of pressure sensitive adhesive heat conductivility is not carried out in patent.
Patent document CN105969253A discloses a kind of ultraviolet light curing pressure sensitive composite and pressure sensitive adhesive, by regulating and controlling to live
The mass ratio of property diluent and oligomer so that the adhesive property of UV solidified pressure-sensitives greatly improves, wherein oligomer polyolefin
The effect of olefin functionalities in acrylate so that UV solidified pressure-sensitives have stronger ageing-resistant, water-fast, resistance to optically-active without sending out
The characteristics such as raw xanthochromia.The research of pressure sensitive adhesive heat conductivility is not carried out in the patent equally.
The heat conductivility and adhesive property of adhesive tape have vital shadow to the heat dissipation effect and durability of electronic product
It rings, also, pressure sensitive adhesive needs have moderate viscosity, in order to the processing that forms a film.Therefore, it develops a kind of excellent thermal conductivity, glue
Knot performance is good, modest viscosity heat conduction pressure sensitive adhesive is particularly important.
Invention content
The object of the present invention is to provide a kind of UV to cure heat conduction pressure sensitive adhesive, and UV curing heat conduction pressure sensitive adhesives have good
Heat conductivility and adhesive property, and modest viscosity is easy to form a film.
It is a further object of the invention to provide a kind of preparation method of above-mentioned UV curings heat conduction pressure sensitive adhesive, the preparations
Method processing step is simple, and pollution is small.
To achieve the above object, technical solution proposed by the present invention is:
A kind of UV cures heat conduction pressure sensitive adhesive, which is characterized in that by weight including consisting of raw material:
10~30 parts of acrylic ester prepolymer;
70~90 parts of heat filling;
And photoinitiator;
In the acrylic ester prepolymer, the acrylic acid including accounting for acrylic ester prepolymer mass percent 70%~90%
The acrylic acid or hydroxy-ethyl acrylate of different monooctyl ester and mass percent 10%;
The heat filling includes unformed aluminium oxide or ball-aluminium oxide.
The present invention uses particular kind of acrylic ester prepolymer and particular kind of heat filling, and by the acrylate
Prepolymer and heat filling are compounded according to special ratios.It interacts between acrylic ester prepolymer and heat filling so that should
Pressure sensitive adhesive has good heat conductivility, excellent adhesive property and a faster curing rate, thermal conductivity factor for 0.5~
2W/ (mK), 180 ° of peel strengths are between 10~50N/25mm.
Above-mentioned UV curing heat conduction pressure sensitive adhesives, it is preferred that further included in the acrylic ester prepolymer:Ethyl acrylate,
Butyl acrylate, isobornyl acrylate, acrylonitrile, methyl acrylate, vinylacetate, methyl methacrylate, methyl-prop
Olefin(e) acid, octadecyl acrylate, glycidyl methacrylate, hydroxy-ethyl acrylate, hydroxyethyl methacrylate, metering system
Sour hydroxypropyl acrylate, neopentyl glycol dimethacrylate, two amido ethylmethyl acrylates, Diacetone Acrylamide, N- hydroxyl first
One or more of base acrylamide, N- butoxy methyl acrylamides, vinyl silanes and vinyl silicone oil.It adds in above-mentioned
Substance is total to as the modified monomer of acrylic ester prepolymer or sticky monomer or interior polycondensation monomer by modified monomer and sticky monomer
The acrylate copolymer containing polar functional group is obtained after poly-.The very big functional group of these polarity can make the interior of pressure-sensitive adhesive
Poly- intensity and adhesive property significantly improve.And adding in for interior polycondensation monomer can be as the control of prepolymer cures speed and viscosity
Agent.
Above-mentioned UV curings heat conduction pressure sensitive adhesive, it is preferred that the viscosity of the acrylic ester prepolymer for 200mPa.s~
1000mPa.s。
Above-mentioned UV curing heat conduction pressure sensitive adhesives, it is preferred that the grain size of the unformed aluminium oxide and ball-aluminium oxide is 800
The mesh of mesh~8000, unformed aluminium oxide and ball-aluminium oxide are the mixture with different-grain diameter particle.In this way, small particle
Filler can be filled in the gap between large particle size filler, be more conducive to form thermal conducting path, further improve leading for pressure sensitive adhesive
Hot property.
Above-mentioned UV curing heat conduction pressure sensitive adhesives, it is preferred that also containing titanium oxide, zinc oxide, oxidation in the heat filling
One or more of magnesium, silicon carbide, nickel oxide, hexagonal boron nitride, silicon nitride, aluminium nitride, these fillers are that insulation is filled out
Material is conducive to realize the effect of insulating heat-conductive in electronic product;It is added in unformed aluminium oxide or ball-aluminium oxide above-mentioned
Insulating packing is conducive to further improve the heat conductivility of pressure sensitive adhesive.
Above-mentioned UV curing heat conduction pressure sensitive adhesives, it is preferred that the matter of unformed aluminium oxide or ball-aluminium oxide in heat filling
Score >=60% is measured, if the content of aluminium oxide is too low, the heat-conducting effect of pressure sensitive adhesive improves unobvious.
Above-mentioned UV curings heat conduction pressure sensitive adhesive, it is preferred that the photoinitiator is TPO, 184,1173,369,907,819,
In MOBB, PBZ, MBZ, MBF, CBP, DETX, BP+P115, BP+EDB, BP+EDBA, ITX+EDBA, ITX+P115, ITX+EDB
One or more.Further preferably, the photoinitiator is TPO.
Above-mentioned UV curing heat conduction pressure sensitive adhesives, it is preferred that the additive amount of the photoinitiator is the acrylate prepolymer
5 ‰~the 5% of object additive amount.If photoinitiator levels are too low, will be not enough to cause polymerization or efficiency of initiation reduction, curing rate
Slowly, low production efficiency;If the too high levels of photoinitiator will cause unnecessary waste, and can lead to surface aggregate speed
With the increase of the ratio between inside body rate of polymerization, there are different internal stress, lead to coating shrinkage, part can be also generated in pressure sensitive adhesive
Non-cured materials, the Chemical Physics performance of weaken coating.
A kind of preparation method of the UV curing heat conduction pressure sensitive adhesives of present invention, includes the following steps:
(1) photoinitiator is added in acrylate prepolymer body by proportioning, is sufficiently stirred dissolving, obtains Acrylate pressure sensitive
Sol solution;
(2) heat filling is stirring evenly and then adding into acrylate pressure-sensitive adhesive solution obtained by step (1), continues to stir
It mixes, obtains heat-conducting glue in the pasty state;
(3) heat-conducting glue obtained by step (2), then with release film mulching starvation, is placed in UV coated on polyester film
Cure under lamp and cure heat conduction pressure sensitive adhesive to get UV.
The preparation method of above-mentioned UV curings heat conduction pressure sensitive adhesive, it is preferred that in the step (3), illumination energy during curing
It measures as 150mJ/cm2~768mJ/cm2, hardening time is 120s~600s.
The preparation method of above-mentioned UV curings heat conduction pressure sensitive adhesive, it is preferred that the thickness of the UV curings heat conduction pressure sensitive adhesive is
150 μm~1000 μm.
Compared with prior art, the advantage of the invention is that:The UV curing heat conduction pressure sensitive adhesives of the present invention, using particular types
Acrylic ester prepolymer and heat filling, and be used in compounding according to special ratios, UV curing heat conduction pressure sensitive adhesive heat conductivilitys
Well, adhesive property is excellent, curing rate is fast, and thermal conductivity factor is 0.5~2W/ (mK), and 180 ° of peel strengths are in 10-50N/
25mm.The volatilizable ingredient of preparation method of the present invention is almost nil, and environmental pollution is small, easy to operate, and low energy consumption, at low cost.
Specific embodiment
For the ease of understanding the present invention, present invention work more comprehensively, is meticulously described below in conjunction with preferred embodiment,
But the protection scope of the present invention is not limited to the following specific embodiments.
Unless otherwise defined, all technical terms used hereinafter and the normally understood meaning of those skilled in the art
It is identical.Technical term used herein is intended merely to the purpose of description specific embodiment, is not intended to the limitation present invention
Protection domain.
Unless otherwise specified, various raw material, reagent, the instrument and equipment etc. used in the present invention can pass through city
Field is commercially available or can be prepared by existing method.
Heretofore described mix monomer refer both to ethyl acrylate, butyl acrylate, isobornyl acrylate, acrylonitrile,
Methyl acrylate, vinylacetate, methyl methacrylate, methacrylic acid, octadecyl acrylate, Glycidyl methacrylate are sweet
Grease, hydroxy-ethyl acrylate, hydroxyethyl methacrylate, hydroxy propyl methacrylate, neopentyl glycol dimethacrylate, two
Amido ethylmethyl acrylate, Diacetone Acrylamide, N hydroxymethyl acrylamide, N- butoxy methyl acrylamides, second
Two or more mixtures in alkenyl silanes or vinyl silicone oil.
Heat filling used is provided by Nanjing Tian Hang new materials Co., Ltd in 1-15 of the embodiment of the present invention.
Embodiment 1:
A kind of preparation method of the UV curing heat conduction pressure sensitive adhesives of the present invention:
(1) with glue
Photoinitiator (TPO) is added in acrylic ester prepolymer and is sufficiently stirred dissolving (can low-grade fever), obtains acrylate
Pressure-sensitive sol solution, wherein, the addition of TPO is the 0.5% of acrylic ester prepolymer quality;By heat filling (spherical Al2O3)
It is uniformly mixed, is added in acrylate pressure-sensitive adhesive solution under high speed agitator, continue the stirring under high speed agitator and applied to easy
The paste of film, wherein, the mass ratio of heat filling and acrylic ester prepolymer is 70:30.
Wherein, Isooctyl acrylate monomer 70%-90%, acrylic acid 10%, the different ice of acrylic acid are included in acrylic ester prepolymer
Piece ester 0%-20%.Photoinitiator TPO accounts for the 0.1%-0.5% of acrylic ester prepolymer total weight.The acrylic ester prepolymer
Preparation method it is as follows:Above-mentioned raw materials are uniformly mixed according to a ratio, under nitrogen protection, ultraviolet lighting is reacted to viscosity 200-
1000mPas, then blowing air terminate reaction to get.
(2) film
By the heat-conducting glue of paste obtained by step (1) coated on polyester film, then with release film mulching starvation, by it
It is placed under UV lamp and cures 120s (light energy 150mJ/cm2) -600s (light energy 768mJ/cm2), obtain no-solvent type
UV cures heat conduction pressure sensitive adhesive.
In the present embodiment, spherical shape Al used2O3Grain size in the range of the mesh of 800 mesh~8000, be a variety of different-grain diameter particles
Mixture.The thermal conductivity factor of UV curings heat conduction pressure sensitive adhesive obtained by the embodiment is tested, test result is as shown in table 1.
Embodiment 2-5:
The preparation method of embodiment 2-5 is same as Example 1, and only the quality of heat filling and acrylic ester prepolymer is matched
Than difference.
The thermal conductivity factor of UV curings heat conduction pressure sensitive adhesive obtained by embodiment 2-5 is tested, test result and heat conduction are filled out
Material is as shown in table 1 with the quality proportioning of acrylic ester prepolymer.
Embodiment 6-8:
The preparation method of embodiment 6-8 is same as Example 1, and only the quality of heat filling and acrylic ester prepolymer is matched
Than difference, the adding proportion of heat filling used is different, and the type of photoinitiator used and additive amount are different.
The thermal conductivity factor of UV curings heat conduction pressure sensitive adhesive obtained by embodiment 6-8 is tested, test result and heat conduction are filled out
The type of material and its as shown in table 1 with the quality proportioning of acrylic ester prepolymer.
Embodiment 9-11:
The preparation method of embodiment 9-11 is same as Example 1, only the quality of heat filling and acrylic ester prepolymer
Proportioning is different, and the adding proportion of heat filling used is different.
The thermal conductivity factor of UV curings heat conduction pressure sensitive adhesive obtained by embodiment 9-11 is tested, test result and heat conduction are filled out
The type of material and its as shown in table 1 with the quality proportioning of acrylic ester prepolymer.
Embodiment 12-13:
The preparation method of embodiment 12-13 is same as Example 1, only the quality of heat filling and acrylic ester prepolymer
Proportioning is different, and the type of heat filling used and adding proportion are different.
The thermal conductivity factor of UV curings heat conduction pressure sensitive adhesive obtained by embodiment 12-13 is tested, test result and heat conduction
The type of filler and its as shown in table 1 with the quality proportioning of acrylic ester prepolymer.
Embodiment 14-15:
The preparation method of embodiment 14 and embodiment 15 is same as Example 1, during only acrylic ester prepolymer is formed
Acrylic acid change hydroxy-ethyl acrylate into, and the type of heat filling and its with the quality proportioning of acrylic ester prepolymer not
Together.
The thermal conductivity factor of 14 and 15 gained UV of embodiment curing heat conduction pressure sensitive adhesives is tested, test result and heat conduction
The quality proportioning of filler and acrylic ester prepolymer is as shown in table 1.
Table 1UV cures the formula (wt%) of heat conduction pressure sensitive adhesive and Determination of conductive coefficients result
By embodiment 1-5 in table 1 it is found that when heat filling uses one-component spherical shape Al2O3When, with spherical Al2O3Content
Increase, thermal conductivity factor gradually increases;But with spherical Al2O3The viscosity of the increase system of content can also increase, curtain coating
Property decline, be unfavorable for post-production film forming.Comprehensive various aspects consider that the thermal conductivity factor of the pressure sensitive adhesive of embodiment 3 is higher, and its
Modest viscosity, processing performance are good.
Comparative example 3 and embodiment 6-8 are it is found that lead heat conduction pressure sensitive adhesive using different photoinitiators in pressure sensitive adhesive
Hot index impacts are smaller.Experiment finds that 184 photoinitiators are not readily dissolved in prepolymer, need low-grade fever;And 1173 light of liquid draws
The efficiency of initiation for sending out agent is low compared with TPO, it is therefore preferable that using TPO as photoinitiator.
Comparative example 3 and embodiment 9-11 is it is found that the thermal conductivity factor of the heat conduction pressure sensitive adhesive of different-thickness is different, with 500 μ
On the basis of m, its fluctuation range is about in 4%-10% in 150-1000 μm for bound, and thermal conductivity factor increases with the thickness of sample
And increase.
Comparative example 2 and embodiment 12-15 are it is found that use composite heat-conducting filler ratio single use aluminium oxide thermal conductivity factor
It is high.Since for density there are a degree of difference, the different heat filling volume fractions of equal parts are poor between different heat fillings
It is different larger, there is large effect to system viscosity, and form thermal conducting path to pressure sensitive adhesive also to have a degree of influence, therefore,
Consider system viscosity and thermal conductivity factor, it is preferred to use spherical Al2O3With AlN as composite heat-conducting filler (referring to embodiment
13)。
180 ° of peel strengths of the UV curing heat conduction pressure sensitive adhesives of section Example are tested, test result such as table 2
It is shown.Wherein, embodiment 3 tests three groups of data that thickness is 150 μm, 300 μm and 500 μm respectively.
2 part UV of table cures 180 ° of peel strength test results of heat conduction pressure sensitive adhesive
By embodiment 1-4 in table 2 it is found that with the decline of prepolymer number in system, the peel strength of heat conduction pressure sensitive adhesive
It is gradually reduced, but peel strength is all higher than 15N/25mm, peel strength is moderate.Since the system viscosity of embodiment 5 is larger, measure
Heat conduction pressure sensitive adhesive when thickness is 500 μm also has the peeling force of some strength.By three groups of embodiments 3 as it can be seen that in different-thickness
Under in a certain range its peel strength with thickness of sample increase and increase.By embodiment 12-15 it is found that working as Al2O3Heat filling
Account for leading, when adding other a small amount of heat fillings, the peel strength difference of heat conduction pressure sensitive adhesive is smaller, and peel strength is moderate.
To sum up, to have had both preparation process pollution-free for the no-solvent type UV curing heat conduction pressure sensitive adhesives of the present invention, it is volatilizable
Ingredient is almost nil, and curing rate is fast, and thermal conductivity is high, and adhesive property is good, modest viscosity, is easy to the advantages that film forming is processed.In glue
Liquid is coated on when being in paste viscous liquid easy to apply on base material, by UV radiation curings into the pressure-sensitive of cementability
Glue product, and extend the scope of application of acrylate pressure-sensitive adhesive.
Comparative example 1:
Using method same as Example 1, only the mass ratio of acrylic ester prepolymer and heat filling is 10:90,
The moulding processability of gained UV curing heat conduction pressure sensitive adhesives declines, be not easy to be formed relatively thin coating (<300 μm), but 500 can be formed
The coating of μ m-thick, the viscosity of system can be increased by illustrating the increase of heat filling content, and the content of heat filling should not be too large, otherwise
The processing performance of pressure sensitive adhesive can be reduced.
Comparative example 2:
Using method same as Example 1, only the mass ratio of acrylic ester prepolymer and heat filling is 5:95, institute
UV curing heat conduction pressure sensitive adhesives are obtained caking phenomenon occur, lose machinability.
Comparative example 3:
Using method same as Example 1, only made using 3000 mesh heat conduction aluminium oxide of the AR-30 types of Foshan company
For heat filling, the performed polymer containing acrylic acid modified monomer is used.The glue viscosity of gained pressure sensitive adhesive is larger, cures quickly
Caking phenomenon, it is impossible to processing film forming.This may be that insufficient, pH higher is calcined in preparation process because of the alumina product,
Caused by being reacted with acrylic monomers.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field
For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, that is made any repaiies
Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.