Low dielectric constant polymer composites

Abstract

Disclosed herein is a polymer composition comprising at least one thermoplastic polymer and core / shell particles dispersed therein, the core / shell particles comprising a MgTiO3 core and a SiO2 shell.

Description

[Technical field]

[0001] The present invention relates to a thermoplastic composition having a low dielectric constant and good mechanical properties. [Background technology]

[0002] Thermoplastic polymers have excellent mechanical properties, moldability, and chemical resistance. In the electronics industry, high loadings of inorganic fillers are incorporated into thermoplastic polymers to achieve low dielectric constant (Dk) composites for use as housing or support materials. However, high loadings of inorganic fillers also cause degradation of mechanical properties. Therefore, there remains a need to develop composite thermoplastic compositions with low Dk while maintaining good mechanical properties. Summary of the Invention [Means for solving the problem]

[0003] Provided herein is a low dielectric constant polymer composition comprising: a) at least one thermoplastic polymer; and b) about 5-95 weight % core / shell particles comprising a core formed of MgTiO3 and a shell formed of SiO2, wherein the weight ratio of MgTiO3:SiO2 ranges from about 85:15 to 15:85, and the total weight of the polymer composition totals 100 weight %.

[0004] In one embodiment of the polymer composition, the at least one thermoplastic polymer is present at a level of about 10-80 weight percent, based on the total weight of the polymer composition.

[0005] In a further embodiment of the polymer composition, the at least one thermoplastic polymer is included at a level of about 20-60 weight percent, based on the total weight of the polymer composition.

[0006] In yet a further embodiment of the polymer composition, the at least one thermoplastic polymer is included at a level of about 25-45 weight percent, based on the total weight of the polymer composition.

[0007] In yet further embodiments of the polymer composition, the at least one thermoplastic polymer is selected from the group consisting of polyesters, polyolefins, polyimides, polyamides, polyetherimides, polyaryletheretherketones, polyoxymethylenes, and combinations of two or more thereof.

[0008] In yet a further embodiment of the polymer composition, the core / shell particles have a weight ratio of MgTiO3:SiO2 in the range of about 80:20 to 20:80.

[0009] In yet a further embodiment of the polymer composition, the core / shell particles have a weight ratio of MgTiO3:SiO2 in the range of about 75:25 to 25:75.

[0010] In still further embodiments of the polymer composition, the core / shell particles are included at a level of about 25-85 wt.%, or about 45-75 wt.%, based on the total weight of the polymer composition.

[0011] In yet a further embodiment of the polymer composition, the core / shell particles are included at a level of about 45-75% by weight, based on the total weight of the polymer composition.

[0012] Further provided herein are articles formed from the above polymeric compositions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Disclosed herein is a composite polymer composition having low dielectric constant and good mechanical properties. The composite polymer composition comprises at least one thermoplastic polymer and dispersed therein core / shell particles, the core / shell particles comprising a MgTiO3 core and a SiO2 shell.

[0014] The term "thermoplastic polymer" is used herein to refer to a polymer that turns to a liquid when heated and cools to a rigid state when cooled sufficiently. Thermoplastic polymers useful herein include, but are not limited to, polyesters, polyolefins, polyimides, polyamides, polyetherimides, polyaryletheretherketones, polyoxymethylenes, and mixtures thereof. Exemplary polyesters include, but are not limited to, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polycyclohexylene dimethylene terephthalate (PCT), and the like. Exemplary polyolefins include, but are not limited to, polyethylene, polypropylene, polyolefin elastomers, and the like. Suitable polyesters are commercially available from a variety of vendors. For example, suitable PET is available from DuPont de Nemours, Inc. (USA) (hereinafter "DuPont") under the trade name Rynite®, suitable PBT is available from DuPont under the trade name Crastin® or from Shinkong Synthetics Fibers Corporation (Taiwan) under the trade name Shinite D201, suitable PTT is available from DuPont under the trade name Sorona®, and suitable PCT is available from Celanese Corporation (Switzerland) under the trade name Thermx™. The polyolefins used herein may also be commercially available from a variety of vendors. For example, suitable polypropylenes are available from ExxonMobil under the trade name ExxonMobil™ PP4792E1 or from DOW Corporation (USA) under the trade name DOWLEX™, suitable polyolefin elastomers are available from DOW Corporation (USA) under the trade name ENGAGE™, and suitable ethylene-vinyl acetate copolymers (EVA) are available from DOW Corporation (USA) under the trade name ELVAX™.

[0015] According to the present disclosure, about 10-80 wt. %, or about 20-60 wt. %, or about 25-45 wt. % of the thermoplastic polymer may be present in the composition, based on the total weight of the composition.

[0016] As used herein, a core / shell particle is comprised of a core formed of MgTiO3 and a shell formed of SiO2. According to the present disclosure, the MgTiO3 core is fully or partially coated with a SiO2 shell. The weight ratio of MgTiO3:SiO2 ranges from about 85:15 to 15:85, or from about 80:20 to 20:80, or from about 75:25 to 25:75.

[0017] The core / shell particles used herein can be prepared by a sol-gel process, such as the process disclosed in PCT Patent Application Publication WO201531570 (hereby incorporated by reference). The sol-gel process includes mixing MgTiO3 particles, silica precursor, hydrolyzate, and surfactant (optionally a cationic or amphoteric surfactant) in a solvent to provide a mixed solution. Such mixing causes the silica precursor to chemically react to form a layer of SiO2 coating on the surface of the MgTiO3 particles. The core / shell particles can be removed by filtration from the mixed solution.

[0018] The solvent used in the sol-gel process is an aqueous solution in which the MgTiO3 particles, silica precursor, hydrolysate, and optional surfactant are uniformly dispersed and reacted.Preferably, the solvent used herein is a solvent mixture of water and any one or more of the following: isopropyl alcohol (IPA), methanol, ethanol, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), monoethanolamine (MEA), dipropylene glycol diacrylate (DPGDA), and mixtures of two or more thereof.In one embodiment, the solvent is an aqueous solution of water and one or more of the following: isopropyl alcohol (IPA), methanol, ethanol, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), monoethanolamine (MEA), dipropylene glycol diacrylate (DPGDA). In one embodiment, the solvent can be a mixture of water and one or more of the following: isopropyl alcohol (IPA), methanol, and ethanol. When the solvent is an aqueous solution of water and IPA, methanol, or ethanol, the amount of solvent can range from about 300 to 5000 parts by weight per 100 parts by weight of MgTiO3 particles, and the mass ratio of water to IPA, methanol, and / or ethanol ranges from about 1:3 to about 1:10.

[0019] The SiO2 precursor used in the sol-gel process is the source of the SiO2 shell.

[0020] The SiO2 precursor may be a silicon alkoxide represented by formula (I): (R 1 )nSi(OR 2 ) 4-n (In the formula, R 1 represents a hydrocarbon having 1 to 8 identical or different, substituted or unsubstituted carbon atoms, n represents 0, 1, 2, or 3, R 2(represents a hydrocarbon having 1-8 carbon atoms). The silicon alkoxide reacts with water and a hydrolysis catalyst to produce silica, the entity that coats the MgTiO3 particles.

[0021] The silicon alkoxide can be a tetraalkoxysilane. Alternatively, the tetraalkoxysilane can be tetraethoxysilane, tetramethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraamyloxysilane, tetraoctyloxysilane, tetranonyloxysilane, dimethoxydiethoxysilane, dimethoxydiisopropoxysilane, diethoxydiisopropoxysilane, diethoxydibutoxysilane, diethoxyditrityloxysilane, or a mixture of two or more thereof.

[0022] When the silicon alkoxide is tetraethoxysilane (TEOS, Si(OC2H5)4)), the hydrolysis reaction is Si(OC2H5)4+2H2O→SiO2+4C2H5OH It is.

[0023] The hydrolysis catalyst promotes the hydrolysis reaction of the SiO2 precursor as an acidic hydrolysis catalyst or a basic hydrolysis catalyst. The methods described herein can be used with either an acidic or a basic hydrolysis catalyst. An acidic hydrolysis catalyst promotes the hydrolysis reaction by protonating the oxygen atom, i.e., by releasing protons (H + ) donors, whereas basic hydrolysis catalysts facilitate the reaction by allowing nucleophilic addition via proton transfer from a carbon atom in the hydrolysis. + ) receptor.

[0024] Hydrochloric acid may be preferred as the acidic hydrolysis agent, and ammonium hydroxide may be preferred as the basic hydrolysis catalyst.

[0025] Surfactants are optionally included in the sol-gel process. The surfactants used herein may be cationic surfactants having hydrophilic groups that dissociate into cations in aqueous solution, or amphoteric surfactants that dissociate into both anions and cations in aqueous solution. The surfactants are used in the process as binders for the MgTiO3 particles and silica.

[0026] According to the present disclosure, about 5-95 wt. %, or about 25-85 wt. %, or about 45-75 wt. % of the core / shell particles may be present in the composition, based on the total weight of the composition.

[0027] The polymer compositions disclosed herein may further include other additives such as colorants, antioxidants, UV stabilizers, UV absorbers, heat stabilizers, lubricants, viscosity modifiers, nucleating agents, plasticizers, mold release agents, scratch and mar modifiers, impact modifiers, emulsifiers, optical brighteners, antistatic agents, acid absorbers, odor absorbers, hydrolysis inhibitors, antimicrobial agents, density modifiers, reinforcing fillers, thermally conductive fillers, electrically conductive fillers, coupling agents, endcapping agents, and combinations of two or more thereof. Based on the total weight of the polymer compositions disclosed herein, such further additives may be present at a level of about 0.005 to 30% by weight, or about 0.01 to 25% by weight, or about 0.02 to 20% by weight.

[0028] Further disclosed herein are articles formed from the polymer compositions disclosed herein. Such polymer compositions can be used in various fields, including, for example, electronic, automotive, and communication industries. Exemplary articles formed from the polymer compositions include, but are not limited to, housings, protective, or supporting parts in electronic devices. EXAMPLES

[0029] material PP - Polypropylene obtained from ExxonMobil Corporation under the trade name ExxonMobil(TM) PP4792E1; PBT - Polybutylene terephthalate obtained from Shinkong Synthetic Fibers Corporation under the trade name Shinite™ D201; MgTiO3- MgTiO3 powder obtained from Shanghai Dian Yang Industry Co. Ltd (China); SiO2- SiO2 powder obtained from Lianyungang Donghai SiIica Powder Co., Ltd. C / S(97 / 3) - Core / shell particles prepared as follows: TEOS and deionized water are mixed and dispersed in the solvent. MgTiO 3 Add the particles, continue stirring until the dispersion thickens, and dry the thickened gel product at 70° C. for 24 hours to obtain the core / shell particles. C / S(90 / 10) - core / shell particles prepared as above, the weight ratio of MgTiO3 and SiO2 is 90:10; C / S(70 / 30) - core / shell particles prepared as above, the weight ratio of MgTiO3 and SiO2 is 70:30; · C / S(50 / 50) - core / shell particles prepared as above, with a weight ratio of MgTiO3 and SiO2 of 50:50.

[0030] In each of Comparative Examples CE1-CE6 and Examples E1-E4, the polymer compositions (all components listed in Table 1) were prepared by compounding in an extruder. The barrel temperature was set at about 220° C. and the screw speed was set at about 300 rpm. After exiting the extruder, the blended compositions were cooled and chopped into resin pellets, followed by drying overnight.

[0031] The dried resin pellets obtained in each example were injection molded into test plaques of 60×60×1 mm and the dielectric constant (Dk) values ​​were measured and are reported in Table 1.

[0032] Additionally, for each sample, the tensile stress and tensile strain at break were measured according to ISO 527-2:2012, the bending stress was measured according to ISO 178, and the UN Charpy impact was measured according to ISO 179-1. The results are shown in Table 1.

[0033] As demonstrated herein, when core / shell particles having a weight ratio of MgTiO3:SiO2 between 85:15 and 15:85 were incorporated into thermoplastic polymers (e.g., E1-E4), the dielectric constant (Dk) value was reduced to 3 compared to compositions using MgTiO3 particles or core / shell particles having a weight ratio of MgTiO3:SiO2 less than 15:85. Furthermore, when SiO2 powder was used, a dielectric constant (Dk) value of 3 was achieved, but the mechanical properties of the composition were inferior compared to the examples.

[0034] [Table 1]

Claims

1. a) at least one thermoplastic polymer; b) about 5 to 95 weight percent core / shell particles; wherein the core / shell particles are MgTiO 3 and a core formed of SiO 2 and a shell formed of MgTiO 3 : SiO 2 in a weight ratio ranging from about 85:15 to 15:85; The total weight of the polymer composition totals 100% by weight; A polymer composition having a low dielectric constant.

2. The polymer composition of claim 1, wherein said at least one thermoplastic polymer is present at a level of about 10 to 80 weight percent, based on the total weight of said polymer composition.

3. The polymer composition of claim 2, wherein said at least one thermoplastic polymer is present at a level of about 20-60 weight percent, based on the total weight of said polymer composition.

4. The polymer composition of claim 3, wherein said at least one thermoplastic polymer is present at a level of about 25-45 weight percent, based on the total weight of said polymer composition.

5. 2. The polymer composition of claim 1, wherein the at least one thermoplastic polymer is selected from the group consisting of polyesters, polyolefins, polyimides, polyamides, polyetherimides, polyaryletheretherketones, polyoxymethylenes, and combinations of two or more thereof.

6. The core / shell particles are MgTiO in a range of about 80:20 to 20:

80. 3 : SiO 2 2. The polymer composition of claim 1 having a weight ratio of:

7. The core / shell particles have a MgTiO 3 : SiO 2 7. The polymer composition of claim 6, having a weight ratio of:

8. The polymer composition of claim 1, wherein the core / shell particles are present at a level of about 25-85 wt %, or about 45-75 wt %, based on the total weight of the polymer composition.

9. The polymer composition of claim 8, wherein said core / shell particles are present at a level of about 45-75 wt %, based on the total weight of said polymer composition.

10. An article formed from the polymer composition of any one of claims 1 to 9.

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