A low-viscosity, high-solid content nanoparticle dispersion and its preparation method and application

Abstract

The invention discloses a low-viscosity and high-solid-content nanoparticle dispersion liquid, a preparation method and application thereof. The invention provides a preparation method for the low-viscosity and high-solid-content nanoparticle dispersion liquid, comprising the following steps: selecting a dispersed phase with good toughening effect and no effect on Tg of an epoxy resin; selecting a suitable dispersant to pretreat the dispersed phase; selecting a suitable dispersing method to uniformly disperse the dispersed phase into the dispersant; the mass ratio of the dispersing aid to the dispersed phase is 0.1:100-3.0:100; the mass ratio of the dispersed phase to the dispersant is 25:75-70:30; the D50 of the nanoparticles in the nanoparticle dispersion liquid after dispersion is 0.01μm-3.00μm; and the viscosity of the nanoparticle dispersion liquid at 25°C is 5mPa·s-2000mPa·s. The invention solves the problems of toughening and heat resistance of epoxy resin and the problems of uneven dispersion, difficult addition and easy sedimentation of nanoparticles.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic materials and composite materials, and particularly relates to a low-viscosity and high-solid content nanoparticle dispersion liquid and a preparation method and application thereof. Background Art

[0002] Epoxy resin is a thermosetting resin with excellent comprehensive properties. It is widely used in construction, machinery, electronics, aerospace, shipping, chemical corrosion protection, and other composite materials due to its good adhesion, corrosion resistance, electrical insulation, chemical stability, and processability. However, epoxy resin contains a large number of epoxy groups, and after curing, it has a high cross-linking density, high internal stress, brittleness, poor impact resistance, and crack resistance. Therefore, it is difficult to meet the requirements of engineering technology, and its application is subject to certain restrictions.

[0003] In order to increase the toughness of epoxy resin, people initially adopted the method of adding some plasticizers and flexibilizers, but these low molecular weight substances will greatly reduce the heat resistance, hardness, modulus and electrical properties of the material. Since the 1960s, research on toughening and modification of epoxy resin has been widely carried out at home and abroad. Currently, there are four most commonly used and effective methods: rubber elastomer toughening, thermoplastic resin toughening, hyperbranched polymer toughening and core-shell polymer toughening. The above methods can greatly improve the toughness and physical properties of epoxy resin, but they also have certain defects and must be used for appropriate occasions to truly show the physical properties of epoxy resin.

[0004] Among them, core-shell emulsion polymer refers to a polymer composite or grafted particle obtained by emulsion polymerization of two or more monomers. The inside and outside of the particle are enriched with different components, showing a special double-layer or multi-layer structure; the core and shell have different functions. Compared with traditional rubber toughening, core-shell polymer toughening can maintain the Tg of the original epoxy resin while obtaining good toughness. Core-shell toughening agents appeared earlier and have always been a hot topic of research, but their dispersions generally have high viscosity and low solid content. Application No. 201280076861.7 discloses a masterbatch blend, which contains a solvent and a core-shell rubber, and the content of the core-shell rubber is 5wt%-40wt%. Application No. 201810791025.6 discloses an epoxy resin toughening modifier for composite materials, which is composed of bisphenol A epoxy resin and nano core-shell rubber, and the content of the core-shell rubber is 25wt%. Summary of the invention

[0005] The purpose of the present invention is to provide a low-viscosity and high-solid content nanoparticle dispersion liquid and a preparation method and application thereof.

[0006] The present invention adopts the following technical solutions to achieve the above-mentioned purpose:

[0007] A low-viscosity and high-solid nanoparticle dispersion liquid, made from the raw materials of effective ingredients of the nanoparticle dispersion liquid: nanoparticles, a dispersing aid, and a dispersant.

[0008] A method for preparing a low-viscosity and high-solid content nanoparticle dispersion comprises the following steps:

[0009] Step 1: Material selection: Select nanoparticles with good toughening effect and no influence on Tg of epoxy resin as dispersed phase; the original particle size D50 of the dispersed phase is 0.01 μm-1.00 μm, preferably 0.10 μm-0.60 μm;

[0010] Step 2: Disperse the dispersing aid evenly into the dispersed phase for pretreatment;

[0011] Step 3: Mix the pretreated dispersed phase with the dispersant for pre-dispersion;

[0012] Step 4: further dispersing the pre-dispersed dispersion to obtain a uniformly dispersed nanoparticle dispersion.

[0013] Wherein, the epoxy resin in step 1 is a mixture of one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, alicyclic epoxy resin, linear phenolic epoxy resin, and brominated epoxy resin.

[0014] Wherein, the nanoparticles in step 1 are a mixture of one or more of rubber particles and inorganic nanoparticles.

[0015] The nanoparticles are a mixture of one or more of nitrile rubber powder, core-shell rubber powder, ultra-high molecular weight polyethylene powder, spherical silica powder, spherical alumina powder, zinc oxide powder, talcum powder and the like.

[0016] Wherein, the dispersing aid in step 2 is a wetting agent and a dispersant, and the content of the dispersing aid is 0.1wt%-3.0wt% of the dispersed phase, preferably 0.5wt%-1.5wt% of the dispersed phase.

[0017] Among them, the dispersing agent is HELOXY from HEXION of the United States. TM 61. HELOXY TM 62; MOK-5032, MOK-5010 of MERCK of Germany; BYK-W940, BYK-W980, BYK-W9010 of BYK of Germany; KBM-403, KBM-1003 of Shin-Etsu of Japan, etc., or a mixture thereof.

[0018] Wherein, the dispersant in step three is a combination of one or more of an organic solvent and an epoxy resin, and the content of the dispersant is 30wt%-75wt%, preferably 50wt%-65wt%.

[0019] The organic solvent is a mixture of one or more of alcohols, ketones, ethers, aliphatic hydrocarbons and aromatic hydrocarbons.

[0020] Among them, the organic solvent is a mixture of one or more of methanol, ethanol, isopropanol, methyl ethyl ketone, butanone, cyclohexanone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, dimethylformamide, dimethylacetamide, toluene, and xylene.

[0021] The viscosity of the nanoparticle dispersion at 25° C. is 5 mPa·s-2000 mPa·s, preferably 10 mPa·s-600 mPa·s.

[0022] The D50 of the dispersed nanoparticles in the nanoparticle dispersion is 0.01 μm-3.00 μm, preferably 0.10 μm-0.80 μm.

[0023] The content of the nanoparticles in the nanoparticle dispersion is 25wt%-70wt%, preferably 35wt%-50wt%.

[0024] The dispersion method is a combination of one or more forms of stirring, high shear, ball milling, grinding, ultrasound, emulsification, homogenization, etc.

[0025] Among them, the dispersion and feeding temperatures are both room temperature.

[0026] The invention discloses an application of a low-viscosity and high-solid nanoparticle dispersion, which is used for electronic laminates and composite materials. The nanoparticle dispersion has a significant toughening effect at a relatively low addition amount, and greatly improves the mechanical properties of the substrate without reducing its heat resistance.

[0027] The advantages of the present invention are as follows:

[0028] 1. The nanoparticles are evenly dispersed, small in size, and free of agglomeration.

[0029] 2. Nanoparticle dispersion is not easy to settle and has a shelf life of more than 12 months.

[0030] 3. The nanoparticle dispersion has a high solid content.

[0031] 4. The nanoparticle dispersion has low viscosity. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 2. It is a schematic diagram showing the comparison of particle sizes of the nanoparticle dispersion of the present invention before and after dispersion;

[0033] Figure 2 It is a schematic diagram of the particle size distribution state of the nanoparticle dispersion of the present invention;

[0034] Figure 3 It is a schematic diagram of the dispersion effect of the nanoparticle dispersion of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described below, but the present invention is not limited to these contents.

[0036] Example 1

[0037] This embodiment provides a low-viscosity and high-solid content nanoparticle dispersion, a preparation method and application thereof, wherein the nanoparticle dispersion has a particle size Dv(50) of 0.22 μm, a solid content of 35 wt %, and a viscosity of 180 mPa·s.

[0038] A method for preparing a low-viscosity and high-solid content nanoparticle dispersion comprises the following steps:

[0039] 1) Disperse 0.18g of German MERCK additive evenly into 35g of rubber particles;

[0040] 2) fully stirring the pretreated rubber particles with 65 g of organic solvent;

[0041] 3) The dispersed liquid after being fully stirred is emulsified to obtain a uniformly dispersed rubber particle dispersion.

[0042] Example 2: This example provides a low-viscosity, high-solid content nanoparticle dispersion, a preparation method and application thereof. The particle size Dv(50) of the nanoparticle dispersion is 0.25 μm, the solid content is 45 wt%, and the viscosity is 260 mPa·s.

[0043] A method for preparing a low-viscosity and high-solid content nanoparticle dispersion comprises the following steps:

[0044] 1) Disperse 0.45g of German BYK additive evenly into 45g of rubber particles;

[0045] 2) subjecting the pretreated rubber particles to sufficient high shear with 55 g of solvent;

[0046] 3) The dispersion liquid after sufficient high shear is subjected to ball milling treatment to obtain a dispersion liquid of uniformly dispersed rubber particles.

[0047] Example 3: This example provides a low-viscosity, high-solid content nanoparticle dispersion, a preparation method and application thereof. The particle size Dv(50) of the nanoparticle dispersion is 0.23 μm, the solid content is 55 wt%, and the viscosity is 620 mPa·s.

[0048] A method for preparing a low-viscosity and high-solid content nanoparticle dispersion comprises the following steps:

[0049] 1) 35 g of rubber particles and 20 g of inorganic nanoparticles were mixed as a dispersed phase, and 0.80 g of Shin-Etsu's silane coupling agent was evenly dispersed into the dispersed phase;

[0050] 2) 35 g of solvent and 10 g of resin were mixed as a dispersant, and the pretreated dispersed phase and the mixed dispersant were fully stirred;

[0051] 3) Grinding the fully stirred dispersion to obtain a uniformly dispersed nanoparticle dispersion.

[0052] The present invention uses the nanoparticle dispersion obtained in the above-mentioned Examples 1-3 to apply to the adhesive system of the electronic laminate / composite material to illustrate the application effect of the present invention. The adhesive system uses an epoxy resin system, as shown in Table 1. The application effects include the following Comparative Examples 1-3 and Examples 1-3, and their toughening effects and heat resistance are shown in Table 2.

[0053] Comparative Example 1: Pure epoxy resin system without any additives.

[0054] Comparative Example 2: Untreated rubber particles were added to the epoxy resin system.

[0055] Comparative Example 3: Untreated inorganic nanoparticles were added to the epoxy resin system.

[0056] Table 1 Epoxy resin adhesive composition (wt%)

[0057]

[0058] Table 2 Specific ratio of each additive (wt%) and its test results

[0059]

[0060] As can be seen from Table 2 above, the nanoparticle dispersion provided by the present invention is a uniform dispersion with high solid content, low viscosity, no agglomeration, and not easy to settle. It can have a significant toughening effect at a relatively low addition amount, greatly improving the mechanical properties of the substrate without reducing its heat resistance; it effectively solves the toughening and heat resistance problems of epoxy resin, and solves the problems of uneven dispersion, difficult addition, and easy sedimentation of nanoparticles.

[0061] It is pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A low-viscosity, high-solid content nanoparticle dispersion, characterized in that: Raw materials for effective ingredients of nanoparticle dispersion: nanoparticles, dispersing aids, and dispersants.

2. The method for preparing a low-viscosity and high-solid content nanoparticle dispersion according to claim 1, characterized in that: The following steps are involved: Step 1: Material selection: select nanoparticles with good toughening effect and no effect on Tg of epoxy resin as dispersed phase; the original particle size D50 of the dispersed phase is 0.01 μm-1.00 μm; wherein the epoxy resin is a mixture of one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, alicyclic epoxy resin, linear phenolic epoxy resin, and brominated epoxy resin; Step 2: Disperse the dispersing aid evenly into the dispersed phase for pretreatment; Step 3: Mix the pretreated dispersed phase with the dispersant for pre-dispersion; Step 4: further dispersing the pre-dispersed dispersion to obtain a uniformly dispersed nanoparticle dispersion.

3. The method for preparing a low-viscosity and high-solid content nanoparticle dispersion according to claim 2, characterized in that: The nanoparticles in step 1 are a mixture of one or more of rubber particles and inorganic nanoparticles.

4. The method for preparing a low-viscosity and high-solid content nanoparticle dispersion according to claim 3, characterized in that: The nanoparticles are a mixture of one or more of nitrile rubber powder, core-shell rubber powder, ultra-high molecular weight polyethylene powder, spherical silicon dioxide powder, spherical aluminum oxide powder, zinc oxide powder, talcum powder and the like.

5. The method for preparing a low-viscosity and high-solid nanoparticle dispersion according to claim 2, characterized in that: The dispersing aid in step 2 is a wetting agent and a dispersing agent, and the content of the dispersing aid is 0.1wt%-3.0wt% of the dispersed phase.

6. The method for preparing a low-viscosity and high-solid content nanoparticle dispersion according to claim 5, characterized in that: The dispersing agent is HELOXY TM 61. HELOXY TM 62; MOK-5032, MOK-5010 of MERCK of Germany; BYK-W940, BYK-W980, BYK-W9010 of BYK of Germany; KBM-403, KBM-1003 of Shin-Etsu of Japan, etc., or a mixture thereof.

7. The method for preparing a low-viscosity and high-solid content nanoparticle dispersion according to claim 2, characterized in that: In the step 3, the dispersant is a combination of one or more organic solvents and epoxy resins, and the content of the dispersant is 30wt%-75wt%.

8. The method for preparing a low-viscosity and high-solid content nanoparticle dispersion according to claim 7, characterized in that: The organic solvent is a mixture of one or more of alcohol, ketone, ether, aliphatic hydrocarbon and aromatic hydrocarbon.

9. The method for preparing a low-viscosity and high-solid content nanoparticle dispersion according to claim 8, characterized in that: The organic solvent is a mixture of one or more of methanol, ethanol, isopropanol, methyl ethyl ketone, butanone, cyclohexanone, methyl isobutyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, dimethylformamide, dimethylacetamide, toluene and xylene.

10. The use of a low-viscosity and high-solid content nanoparticle dispersion according to claim 1, characterized in that: Nanoparticle dispersions are used in electronic laminates and composite materials, and have a significant toughening effect at relatively low addition levels, greatly improving the mechanical properties of the substrate without reducing its heat resistance.

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