CN107674416B

CN107674416B - Liquid crystal polymer material for environment-friendly electroplating and preparation method thereof

Info

Publication number: CN107674416B
Application number: CN201710844149.1A
Authority: CN
Inventors: 金良文; 梁永华; 郑红专
Original assignee: Jiangmen Dengzhongtai Engineering Plastics Co ltd
Current assignee: Jiangmen Dengzhongtai Engineering Plastics Co ltd
Priority date: 2017-09-19
Filing date: 2017-09-19
Publication date: 2020-06-23
Anticipated expiration: 2037-09-19
Also published as: CN107674416A

Abstract

The invention provides a liquid crystal polymer composite for electroplating decoration, which comprises the following raw materials in percentage by weight: 40-90% of liquid crystal polymer, 3-20% of thermoplastic elastomer, 0-30% of polyamide resin, 0-40% of inorganic mineral powder and 0-2% of coupling agent; wherein the thermoplastic elastomer has a melt index higher than that of the liquid crystalline polymer; the invention also provides a preparation method of the liquid crystal polymer material for electroplating decoration; the liquid crystal polymer material can meet the electroplating requirement, can be treated by environment-friendly potassium permanganate roughening solution, is suitable for the development of environment-friendly electroplating, and has electroplating binding force with the surface of an electroplating coating layer of over 10N after electroplating, so that the use safety is ensured, and meanwhile, the liquid crystal polymer material has excellent mechanical property.

Description

Liquid crystal polymer material for environment-friendly electroplating and preparation method thereof

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a liquid crystal polymer material for environment-friendly electroplating and a preparation method thereof.

Background

The plastic electroplating can enable the surface of the plastic product to have metallic luster and beautiful appearance, play a role in decoration, improve the mechanical strength of the surface of the product and prolong the service life; the plastic product has higher stability to external factors such as light, atmosphere and the like, and is not easy to age; the plastic has electric conduction, magnetic conduction and weldability. The plastic electroplating product can be used in the industries of aerospace, shipbuilding, automobiles, electronic and electric appliances, architectural decoration, toys, articles for daily use and the like, and has wide application.

The common plastic product electroplating process has two types: water electroplating and vacuum ion plating.

The vacuum plating mainly comprises: vacuum evaporation, sputter plating, and ion plating. The method is characterized in that various metal and nonmetal films are deposited on the surface of a plastic part in a distillation or sputtering mode under a vacuum condition, and a very thin surface coating can be obtained in such a mode, and meanwhile, the method has the outstanding advantages of high speed and good adhesion, but the price is higher, the types of metal capable of being operated are fewer, and the method is generally used as a functional coating of a higher-grade product.

The water electroplating process is to electroplate the product to be electroplated in chemical electroplating liquid. The water electroplating process is simple, and the requirements from equipment to the environment are not harsh in vacuum ion plating, so that the water electroplating process is widely applied. Plastics that can be used for water plating include: ABS, nylon, polycarbonate, polystyrene and the like, wherein the ABS is used in the largest amount, the electroplating effect is the best, and the process is the most mature.

Liquid Crystal Polymers (LCPs) are intermediate polymers between solid crystals and liquids, and their molecular arrangement is not three-dimensionally ordered as in solid crystals, but rather is not disordered as in liquids, but rather has a certain (one-dimensional or two-dimensional) order. Further, depending on the conditions for liquid crystal formation, there are classified into thermotropic LCP, lyotropic LCP, etc., in which the liquid crystal state of the thermotropic liquid crystal polymer is formed in a solution and the liquid crystal state of the thermotropic liquid crystal polymer is formed in a melt or above a glass transition temperature. The lyotropic liquid crystal can be used for producing fibers or films by a solvent method, and the thermotropic liquid crystal can be used for injection molding, extrusion molding and the like. Thermotropic liquid crystals are more widely applied, and most of the thermotropic liquid crystals which are industrially produced are aromatic polyester LCP. The liquid crystal aromatic polyester has an abnormal regular fibrous structure, special performance and high product strength which are not inferior to metal and ceramic because macromolecular chains of the liquid crystal aromatic polyester are oriented in a liquid crystal state. The high-performance optical fiber has excellent mechanical property, dimensional stability, optical property, electrical property, chemical resistance, self-flame resistance, good processability, good heat resistance and low thermal expansion coefficient, and is widely applied to the fields of electronics, electricity, optical fiber, automobiles, aerospace and the like at present. LCP produced commercially on the market can be classified into three types according to the Heat Distortion Temperature (HDT) from high to low, wherein the HDT is I type when the HDT is more than 250 ℃, the HDT is II type when the HDT is 180-250 ℃, and the HDT is III type when the HDT is less than 180 ℃.

In the prior art, the related researches on the liquid crystal polymer material are numerous, and mainly focus on the aspects of alloying, compatibilization, toughening, strengthening, heat conduction, flame retardance and the like of the liquid crystal polymer material, but related reports on electroplatable liquid crystal polymer materials are not found.

Polyamide (PA) is generally called Nylon (Nylon), is a general name of heterochain polymers containing a repeating structural unit amide group (NHCO-) in a polymer macromolecular chain, is mainly obtained by polycondensation and self-polymerization of dibasic acid and diamine or amino acid lactam, and is a thermoplastic engineering plastic which is developed at the earliest and has the largest use amount. PA has a plurality of varieties and can be divided into semi-aromatic polyamide, wholly aromatic polyamide, aromatic polyamide containing heterocyclic rings and aliphatic polyamide according to the main chain structure, wherein the semi-aromatic nylon is adopted when the amine or acid of the nylon raw material contains benzene rings, and the wholly aromatic polyamide is adopted when the two raw materials contain benzene rings. The semi-aromatic or wholly aromatic polyamide can remarkably improve the heat resistance and rigidity of nylon. Similar to aliphatic polyamides, aromatic polyamides can be prepared by polycondensation of diacids with diamines or by self-polycondensation of amino acids, and semi-aromatic polyamides can be prepared by polycondensation of aromatic diacids (e.g., terephthalic acid) with aliphatic diacids (e.g., nonanediamine), such as nylon 9T.

Thermoplastic elastomer (TPE) is a block copolymer composed of a glassy or semi-crystalline thermoplastic resin and a soft elastomer, has both high elasticity of rubber and thermoplastic processability of thermoplastic resin, and is known as "third-generation synthetic rubber". The structure is characterized in that different resin segments and rubber segments are formed by chemical bonds, the resin segments form physical cross-linking by means of acting force between the segments, the rubber segments are high-elasticity segments with high free rotation capacity, and the plastic segments and the rubber segments are arranged and connected in proper sequence. Due to the structural characteristics of the polymer chain and the reversibility of the crosslinking state, the thermoplastic elastomer shows the physical and mechanical properties of vulcanized rubber, such as elasticity, strength, deformation characteristic and the like at normal temperature, and the physical crosslinking of the plastic section is reversibly changed along with the change of temperature at high temperature, so that the processing characteristic of the thermoplastic plastic is shown. TPE produced industrially at present mainly comprises styrene, olefin, polyurethane, polyester, polyvinyl chloride, phthalein amine, diene, organic fluorine and the like.

The styrene thermoplastic elastomer (TPS or SBC) is a triblock copolymer (SDS) or a multiblock copolymer (SBS) which is composed of a hard polystyrene segment (S) and a soft polybutadiene chain segment (D), wherein the main products are a block copolymer (SBS) which is composed of a soft polybutadiene segment (B), a block copolymer (SIS) which is composed of polyisoprene segment (D) and a SBS hydrogenated product (SEBS). the SBS thermoplastic elastomer is a block copolymer of styrene and butadiene, and is called third-generation synthetic rubber, which has the characteristics of good tensile strength, elasticity, friction resistance, fatigue resistance, easy dyeing, high quality and low price, can be directly injected or extruded, is mainly used for ① production of rubber products, ② is used as a synthetic resin modifier, ③ is used as an adhesive, ④ is used as an asphalt modifier.

Polyolefin-based thermoplastic elastomers (TPOs) are composed of rubber and polyolefin, and the rubber components are generally Ethylene Propylene Diene Monomer (EPDM), Nitrile Butadiene Rubber (NBR) and butyl rubber. The polyolefin component mainly comprises polypropylene (PP) and Polyethylene (PE). TPO has the characteristics of rubber elasticity at normal temperature, small density, high bending elastic modulus, good fluidity, excellent weather resistance, ozone resistance, ultraviolet resistance, good high temperature resistance, good low temperature impact resistance and the like, is easy to process, low in cost and reusable, and is a material with good comprehensive performance.

Polyurethane thermoplastic elastomer (TPU) polyurethane thermoplastic elastomers are a class of polyurethane rubbers and are classified into polyester types and polyether types. The macromolecular chain structure is formed by polar polyurethane or polyurea chain segments (hard segments) and aliphatic polyester or polyether chain segments (soft segments) alternately. The structure of hydrogen bond crosslinking formed among molecules and light crosslinking among macromolecular chains ensures that the high polymer material has plasticity along with the change of temperature. High hardness, good abrasion resistance and good elasticity are the most outstanding characteristics of the elastomers.

Polyester-based thermoplastic elastomers (TPEE) are a class of block copolymers containing hard segments of aromatic polyesters and soft segments of aliphatic polyesters or polyethers. The ratio of hard segments to soft segments determines the hardness and the physico-mechanical properties of the thermoplastic polyester elastomer. The hard segment forms a physical cross-linking point and bears stress, and the soft segment is a freely distributed high-elasticity chain segment and contributes to elasticity. TPEE has good elasticity, wear resistance, excellent flex resistance, excellent heat resistance, good low-temperature flexibility and high low-temperature impact strength.

ABS is an amorphous polymer material, has ivory appearance, is opaque, odorless and tasteless, has no toxicity, has excellent electroplating performance, and is an excellent non-metal electroplating material. The butadiene content in the ABS plastic has great influence on the electroplating effect, and the butadiene mass fraction of the ABS generally used for electroplating is not less than 10 percent and generally is 18 to 24 percent. During electroplating, the elastomer phase (also called rubber phase) formed by butadiene in ABS is etched to form many holes capable of producing 'bait casting' effect during electroplating, and the bottleneck-shaped holes can greatly enhance the binding force of the plating layer

The electroplating process of the ABS plastic comprises the following steps: the first step of stress relief, which aims to reduce the possible deformation of an electroplated object caused by internal stress generated by injection molding; and the second step is oil removal, wherein most of the oil removal agents are alkaline or acidic degreasers to remove oil stains, release agents and impurities which influence subsequent operation during processing or transportation of the workpiece. The main purpose of degreasing is to degrease and deoil,and simultaneously, the surface tension is reduced, and the surface is endowed with hydrophilicity. And coarsening, wherein the purpose of coarsening is to improve the surface roughness and increase the surface area so as to increase the bonding force of the metal coating and the plastic, change the hydrophobic property of the plastic surface into the hydrophilic property, and uniformly wet all parts by water so as to uniformly adsorb metal ions. Two widely adopted chemical roughening formulas for ABS products are as follows: one is Cr0₃-H₂S0₄-H₂An O etching system; one is Cr0₃–H₂S0₄-H₃P0₄Etching systems, all of which contain hexavalent chromium components. Hexavalent chromium is a swallowable poison/inhalative toxicant, and skin contact may lead to allergies; more likely to cause genetic defects, inhalation may be carcinogenic, and there is a persistent risk to the environment. Step four, sensitization, namely absorbing reductive divalent tin ions on the surface of the material to prepare for activation; the fifth step is activation reduction, firstly, a layer of noble metal layer with catalytic activity, such as Ag, is adsorbed on the surface of the material, then, the noble metal layer is reduced, the surface activity can be improved, the deposition speed is accelerated, and attention needs to be paid to cleaning the activating solution on the surface of the material to prevent the subsequent process from being polluted; the sixth step is chemical plating, namely a metal plating layer with uniform plating layer and good continuity is formed on the surface of the material, so that the guarantee is provided for electroplating; the seventh step is electroplating, and the composite electroplating is usually carried out on the surface of the material by adopting three metals of copper, nickel and chromium to form a final surface decorative layer.

At present, the conventional electroplating-grade nylon material mainly uses aliphatic polyamide (PA6 as a main material) resin as a base material, and is filled with a certain proportion of inorganic mineral powder to perform electroplating coating modification on the base material. In the electroplating process, the aliphatic polyamide resin is firstly swelled by the electroplating solution and then permeates into the interior to corrode the inorganic mineral powder in the material, so that the effect of surface roughness is formed, and the surface bonding force between the electroplated metal layer and the nylon substrate is increased. The surface treatment of polyamides is usually carried out using a solution of sulfuric acid and chromic acid, as in US5, 324, 766. However, the use of the heavy metal chromic acid is extremely hazardous to workers and also causes a great pollution to the environment. The organic components and other chemicals contained in the expansion system can remove some of the fillers from the nylon plastic, which makes some nylon plastics more difficult or impossible to plate because not all of the fillers are removed. In nylon electroplating, coarsening and expansion processes are key factors influencing the appearance quality and the bonding force of a plating layer, and the uniform coarsening effect of the surface of a workpiece can lay a solid foundation for obtaining a subsequent decorative plating layer with good bonding force. Whether the surface roughening is uniform directly determines the electroplating quality of the surface of the nylon workpiece. The existing electroplating nylon material has the following major defects: 1. special nylon electroplating liquid medicine is needed; 2. the base material has low electroplating binding force and cannot meet the requirement of the adhesiveness of a metal electroplating product; 3. the production is not flexible, the cost is high, the cost of the traditional nylon electroplating process is about 2.4 yuan/DM, and the cost of the ABS electroplating process is about 1.2 yuan/DM. Therefore, the market application is not as wide as ABS.

Disclosure of Invention

In view of the problems in the prior art, an object of the present invention is to provide a liquid crystal polymer composite for environmental protection electroplating, which uses a liquid crystal polymer as a main resin, and uniformly distributes an elastomer on the surface of the resin during a mixing modification process by adding a special thermoplastic elastomer. The liquid crystal polymer compound can be used for electroplating treatment, and surface metallization coating is carried out by an electroplating process, so that the liquid crystal polymer compound has excellent heat resistance and electroplating property, excellent dimensional stability and hydrolysis resistance, and especially excellent base material electroplating binding force. It is another object of the present invention to provide a method for preparing a liquid crystalline polymer composite for electro-plating decoration. It is yet another object of the present invention to provide a liquid crystal polymer composite that can be electroplated using an ABS electroplating process.

In order to achieve the purpose, the invention adopts the following technical scheme:

a liquid crystal polymer composite for electroplating decoration comprises the following raw materials in percentage by weight:

wherein the thermoplastic elastomer has a melt index higher than that of the liquid crystalline polymer.

Preferably, the liquid crystalline polymer is an aromatic copolyester.

More preferably, the aromatic copolyester refers to aromatic polyester containing an aromatic ring structure in a molecular main chain, and the aromatic copolyester can be obtained by polycondensation of dibasic acid and dihydric phenol both containing a benzene ring structure, and can also be obtained by self-polycondensation of a bifunctional structure of a benzene ring structure containing carboxyl and hydroxyl at the same time.

Further preferably, the aromatic copolyester polymerized unit is selected from one or more of 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 1, 4-phthalic acid, 1, 3-phthalic acid and 4, 4' -dihydroxybiphenyl.

Further preferably, the aromatic copolyester has a melting point below 330 ℃ and a heat distortion temperature above 200 ℃.

Preferably, the polyamide resin is at least one of an aromatic polyamide resin, a semi-aromatic polyamide resin, and an aliphatic polyamide resin.

More preferably, the aromatic polyamide resin is an aromatic polyamide having an aromatic ring structure in a molecular main chain, and the aromatic polyamide resin may be obtained by polycondensation of a dibasic acid and a diamine each having a benzene ring structure, or by self-polycondensation of an amino acid.

Further preferably, the semi-aromatic polyamide resin may be obtained by polycondensation of an aromatic dibasic acid (e.g., terephthalic acid) and an aliphatic dibasic acid (e.g., hexamethylenediamine), or polycondensation of an aromatic diamine (e.g., p-phenylenediamine) and an aliphatic diamine (e.g., adipic acid).

More preferably, the semi-aromatic polyamide is selected from poly (m-xylylene adipamide) (polyamide MXD, 6), poly (dodecamethyleneterephthalamide) (polyamide 12, T), poly (decamethyleneterephthalamide) (polyamide 10, T), poly (nonanediamide terephthalamide) (polyamide 9, T), hexamethyleneadipamide/hexamethyleneterephthalamide copolyamide (polyamide 6, T/6, 6), hexamethyleneterephthalamide/2-methylpentamethylenediamine copolyamide (polyamide 6, T/D, T), hexamethyleneadipamide/hexamethyleneterephthalamide/hexamethylenediamine isophthalamide copolyamide (polyamide 6, 6/6, T/6, I), poly (caprolactam-hexamethyleneterephthalamide) (polyamide 6/6, t) is added.

Further preferably, the aliphatic polyamide resin means that the polyamide is derived from one or more aliphatic diamines (e.g., aliphatic C)₆-C₂₀Alkylenediamines, cycloaliphatic diamines, preferably diamines including bis (p-aminocyclohexyl) methane, 1, 6-hexanediamine, 2-methylpentanediamine, 2-methyloctanediamine, trimethyl 1, 6-hexanediamine, 1, 8-octanediamine, 1, 9-nonanediamine, 1, 10-decanediamine, 1, 12-dodecanediamine, and m-xylenediamine) and one or more dicarboxylic acids (e.g. adipic acid, sebacic acid, azelaic acid, dodecanedioic acid or their derivatives), and/or one or more aliphatic lactams, amino acids (e.g. 11-aminododecanoic acid, caprolactam and laurolactam).

More preferably, the aliphatic polyamide resin is selected from one or more of PA6, PA66, PA6/66, PA56, PA46, PA610, PA612, PA11, PA12, PA 910, PA 912, PA 913, PA 914, PA 915, PA 616, PA 936, PA1010, PA 1012, PA 1013, PA 1014, PA 1210, PA 1212, PA 1213, PA 1214, PA1313, PA 614, PA613, PA 615, PA 616, and PA 613.

More preferably, the polyamide is selected from at least one of PA6, PA46, PA66, PA6T/66, PA6T/6I, PA612, PA11, PA12, PA9T, PA10T, PA12T, MAXD 6.

Preferably, the thermoplastic elastomer is at least one of a polyolefin elastomer, a polyester elastomer, and a polystyrene elastomer. More preferably, the thermoplastic elastomer may be chemically modified with maleic anhydride, silicone (silane), chlorine, amine, acrylic, epoxy compound, or the like.

More preferably, the polyolefin elastomer is selected from ethylene-propylene-diene rubber (EPDM), ethylene-propylene rubber (EPM), or EPDM and EPM blend, ethylene- α -olefin copolymer, modified ethylene- α -olefin copolymer, reactor directly prepared thermoplastic polyolefin (reactor TPO) in the ethylene- α -olefin copolymer, such as ethylene and propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, α -olefin copolymer, as the modified ethylene- α -olefin copolymer, can be cited the ethylene- α -olefin copolymer side chain or polymer end using maleic anhydride, silicone (silane), chlorine, amine, acrylic acid, epoxy compounds and other chemical modification.

Further preferably, the polystyrene elastomer is selected from one or more of styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene butylene-styrene block copolymer (SEBS), styrene-isobutylene block copolymer (SIB), styrene-isobutylene-styrene block copolymer (SIBs), styrene-ethylene propylene-styrene block copolymer (SEPS).

Further preferably, the polyester elastomer is a polyether-ester block copolymer or a polyester-ester block copolymer. Specifically, the polyester elastomer is selected from materials obtained by ester exchange and polycondensation reactions using dimethyl terephthalate, 1, 4-butanediol, polytetramethylene ether glycol (PTMG) as a raw material. More preferably, the polyester elastomer is a polybutylene naphthalate (PBN) elastomer, a polybutylene terephthalate (PBT) elastomer, or the like.

Preferably, the thermoplastic elastomer has a melt index of > 2g/10min, test conditions: 220 ℃ and 2.16 kg. The melt index of the thermoplastic elastomer is higher than that of the polyamide resin, so that the thermoplastic elastomer can migrate outwards and is distributed on the surface layer of the liquid crystal polymer compound during mixing modification and injection molding.

Preferably, the inorganic mineral powder is at least one selected from the group consisting of alumina, silica, talc, titanium oxide, zinc oxide, montmorillonite and kaolin. Further preferably, the inorganic mineral powder is at least one of talcum powder, alumina, silica, zinc oxide and montmorillonite. The particle size and the mesh number of the inorganic mineral powder are more than 1500 meshes. Particularly preferably, the average particle size of the inorganic mineral powder is 0.1 to 1 μm, wherein the particle size is a median particle size (D50) measured by a laser particle size tester, and the particle size distribution of the inorganic mineral powder is in a normal distribution.

In the invention, the inorganic mineral powder needs to be depolymerized if the particle size of the inorganic mineral powder cannot meet the distribution requirement, and the inorganic mineral powder is prevented from being crushed as much as possible while the mineral powder particles are depolymerized during the depolymerization treatment, because a large number of fine particles exist in the crushed inorganic mineral powder, the specific surface area is further increased, the agglomeration among the inorganic mineral powder is increased, the uniform dispersion of the inorganic mineral powder in the polyamide compound is not facilitated, and the inorganic mineral powder mainly plays a role in increasing the mechanical strength and the temperature resistance of the material.

Further preferably, the inorganic mineral powder is modified by a coupling agent, wherein the weight ratio of the coupling agent to the inorganic mineral powder is 1:20-1: 100.

The coupling agent contains a reactive group, one end of which can form a covalent bond or a hydrogen bond with a hydroxyl group of the inorganic material, and the other end of which forms a hydrogen bond or a covalent bond with the organic material. Therefore, the interfaces of the inorganic material and the organic material are organically connected, and various performances of the composite material are improved.

Preferably, the coupling agent is at least one selected from epoxy silane coupling agent, amino silane coupling agent, mercapto silane coupling agent, ureido silane coupling agent, isocyanate silane coupling agent, titanate coupling agent, borate coupling agent, aluminum-titanium composite coupling agent and aluminate coupling agent.

The inorganic mineral powder modified with the coupling agent is modified by a method such as a usual dipping method, a spraying method, or a spraying method, and the modification method is not particularly limited in the present invention. According to the process design, any method of more uniformly contacting and adsorbing the inorganic mineral powder and the solution containing the coupling agent can be used.

The impregnation method is to put the ore powder into a solution containing a coupling agent, to generate a capillary pressure due to the action of surface tension, to allow the liquid to penetrate into the capillary so that the coupling agent gradually diffuses and adsorbs on the surface and in the micropores of the ore powder, and to remove the remaining solution by drying or roasting after the impregnation is balanced. The spraying method and the spraying method are that the liquid containing the coupling agent is directly sprayed on the surface of the mineral powder, and the spraying method has larger liquid drops due to different nozzle outlets, and is generally suitable for blocky materials and granular materials, while the spraying method is mostly suitable for powder materials. The impregnation method has the advantages of high utilization rate of active components, low cost and simple production method, but the drying process can cause the migration of the active components, and the spraying method have higher efficiency for treating the mineral powder and are easier to dry, but additional equipment is required to be added.

The amino silane coupling agents include gamma-aminopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, N- β (aminoethyl) gamma-aminopropyltrimethoxysilane, N-3- (4- (3-aminopropoxy) butoxy) propyl-3-aminopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, N- β (aminoethyl) gamma-aminopropyltrimethoxysilane, N-3- (4- (3-aminopropoxy) butoxy) propyl-3-aminopropyltrimethoxysilane, the isocyanate silane coupling agents include gamma-isocyanatopropyltriethoxysilane, isocyanatopropyltrimethoxysilane, the ureido silane coupling agents include gamma-ureidopropyltriethoxysilane, gamma-ureidopropyltrimethoxysilane, the triisopropyltitanate coupling agents include isopropyl stearate, titanium trioctyl titanate, dioctylphosphate, di-octyltitanate phosphate, di-octyloctyltitanate phosphate, di-octyloctyloctyltitanate phosphate, di-octyloctyloctyloctylphthalate, di-octyloctyloctyloctyltitanate phosphate, di-octyloctyltitanate phosphate, di-octylphthalate, di-titanate, di-octylphthalate.

Preferably, the liquid crystalline polymer composite further comprises one or more of a fibrous reinforcement, a color masterbatch, a nucleating agent and an antioxidant.

In the invention, the fiber reinforced material comprises one or more of glass fiber, carbon fiber, aramid fiber and wollastonite. The fibrous reinforcing material is added in an amount of not more than 40% by weight based on the total weight of the liquid crystalline polymer composite.

Wherein the glass fiber has a non-circular cross section, which means that the long axis of the glass fiber is perpendicular to the longitudinal direction of the fiber and corresponds to the longest straight line distance in the cross section. A minor axis of the non-circular cross-section in a direction perpendicular to the major axis having a longest linear distance in the corresponding cross-section. The non-circular cross-section of the fiber can have a variety of shapes including a cocoon-shaped (number eight) shape, a rectangular shape, an elliptical shape, a semi-elliptical shape, a roughly triangular shape, a polygonal shape, and a rectangular shape. Those skilled in the art will appreciate that the cross-section may have other shapes. The ratio of the length of the major axis to the length of the minor axis is preferably between about 1.5: 1 and about 6: 1. More preferably, the ratio is between 2: 1 and 5: 1, but more preferably between 3: 1 to about 4: 1. The glass fibers may be in the form of long glass fibers, chopped glass fibers, or other suitable forms known to those skilled in the art.

The carbon fiber is one or more of acrylonitrile-based carbon fiber, asphalt-based carbon fiber, viscose-based carbon fiber or phenolic carbon fiber. The atomic structure of the carbon fiber is similar to that of graphite, the carbon atom layers are arranged in a regular hexagonal pattern, and the interlayer spacing between layers reaches 0.344nm due to the existence of sp3 bonds. The tensile strength of the carbon fiber is 2-7GPa, the elastic modulus is 200-900GPa, and the density is 1.78g/cm³. The carbon fibers may be T300, T700, T800, T1000 of Dongli corporation, P-1002K, P-100S2K, P-1202K, P-120S2K of Cytec Thronel series, and the like.

The aramid fiber is poly phenylene terephthalamide, which is a novel synthetic fiber mainly comprising para-aramid fiber (PPTA) and meta-aramid fiber (PMIA).

The wollastonite is a non-toxic natural mineral, and the wollastonite produced in nature is generally a fibrous, needle-like or radial aggregate, and a plate-like or plate-column-like single crystal extending along the b-axis. The wollastonite has low solubility in neutral water, low oil absorption, no crystal water, low hygroscopicity, no dehydration problem during heating, high melting point, small thermal expansion coefficient, good heat resistance stability, corrosion resistance, weather aging resistance, and good mechanical and electrical properties. After resin filling, the dimension stability is good, and the friction resistance and the smoothness are good; compared with the platy fillers such as talcum powder, mica and the like, the surface scratch-resistant filler has the characteristic of scratch resistance. The wollastonite has good dispersibility in resin, small strength reduction degree and low melt strength after filling materials. The molding processability of the material is also improved due to the moisture absorption and the reduction in viscosity. Preferably, the particle size of the wollastonite is 200-800 meshes; more preferably 400-600 mesh. The wollastonite is modified by a silane coupling agent.

Further preferably, the antioxidant is added in an amount of not more than 2% by weight based on the total weight of the liquid crystal polymer composite, and is divided into a primary antioxidant and a secondary antioxidant, the primary antioxidant is a compound capable of scavenging free radicals such as aromatic amines and hindered phenols and derivatives thereof, and the secondary antioxidant is an organic compound capable of decomposing hydroperoxides and containing phosphorus and sulfur, the primary antioxidant is one or more selected from tetrakis [ methyl- β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] pentaerythritol ester, N-octadecyl β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ester, and N, N' -bis- (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexamethylenediamine, and the secondary antioxidant is one or two selected from tris [2, 4-di-tert-butylphenyl ] phosphite and pentaerythritol distearate.

Further preferably, the nucleating agent is added in an amount of not more than 1% by weight based on the total weight of the liquid-crystalline polymer composite. The nucleating agent is an ethylene acrylic acid copolymer, preferably a sodium ion derivative of an ethylene-methacrylic acid copolymer. The nucleating agent has the main functions of improving the crystallization speed of the nylon material, improving the tensile strength and the flexural modulus of the material and enhancing the strength. Liquid crystal polymer material for electroplating decoration

The preparation method of the liquid crystal polymer compound for electroplating decoration is characterized by comprising the following steps:

(1) mixing polyamide resin, liquid crystal polymer and thermoplastic elastomer, and reacting in a high-pressure reaction kettle, an internal mixer or an extruder to obtain a blend for later use;

(2) adding inorganic mineral powder into a high-speed mixer, adding a coupling agent for reaction when the temperature of the inorganic mineral powder is raised to be more than 105 ℃, and taking out for later use, wherein the reaction time is 10-30 minutes;

(3) and (3) adding the blend obtained in the step (1) into a double-screw extruder, adding the inorganic mineral powder treated in the step (2), mixing, and extruding and granulating to obtain the inorganic mineral powder.

The invention has the beneficial effects that:

1. the liquid crystal polymer compound can be treated by adopting the existing ABS plastic electroplating process, so that the enterprise production is low in process cost and easy to maintain;

2. the thermoplastic elastomer in the liquid crystal polymer compound is less in addition amount and distributed on the surface layer of the liquid crystal polymer, so that the basic characteristics of a liquid crystal polymer base material can be kept, and in addition, the thermoplastic elastomer is easily corroded by ABS electroplating liquid medicine to generate holes similar to ABS bait casting effect, so that the coating binding force is improved;

3. the liquid crystal polymer compound can be electroplated by using the existing ABS electroplating hexavalent chromium roughening solution, can also be treated by using the environment-friendly potassium permanganate roughening solution, and is suitable for the development of environment-friendly electroplating.

4. After the liquid crystal polymer compound is electroplated, the electroplating binding force between the liquid crystal polymer compound and the surface of the electroplating coating layer can reach more than 10N, and the use safety is guaranteed.

5. The liquid crystal polymer compound of the invention adopts modified inorganic carbon powder as the filler, has more stable reaction with electroplating liquid medicine, and has the advantages of hydrolysis resistance and high temperature resistance.

Detailed Description

For a better understanding of the present invention, reference will now be made in detail to the following examples.

Method for testing tensile strength

Tensile Strength dumbbell specimens were prepared according to ISO 527-2012 test method for tensile Properties of plastics, at a tensile speed of 2mm/min and with a longitudinal axis of elongation. The tensile strength at failure and the corresponding elongation at break of the test specimen were recorded. The sample should be conditioned for no less than 40 hours at 23 + -2 deg.C (73.4 + -3.6 deg.F) and 50 + -5% relative humidity prior to testing. In the process of the tensile test, the sample is stretched until breaking, and the percentage of distance between gauge length and elongation is recorded as the breaking elongation. Method for testing impact strength

The impact strength was measured according to the Standard test method for Izod impact testing of ISO 180 plastics. In the test, a standard sample is broken by the swinging of a standard pendulum bob, and the recorded energy absorbed by the broken sample is the impact strength of the broken sample. All compression molded specimens should be notched in the plane parallel to the direction of compression molding application. The parallelism of one face of the notch and the other face is kept within 0.025mm (0.001in) by removing a small amount of material during the machining process, so as to keep within the tolerance of the depth of the sample. The master samples were conditioned for not less than 40 hours at 23 + -2 deg.C (73.4 + -3.6 ℉) and 50 + -5% relative humidity after notching and prior to testing. For testing, it is desirable to perform the test at 23 + -2 deg.C (73.4 + -3.6 deg.F) and 50 + -5% relative humidity.

Method for testing bending performance

The bending properties were measured according to ISO 178-2010 plastic bending property determination. Wherein the bending strength is the maximum stress borne by the material when the material is cracked under the bending load or reaches the specified deflection, the bending modulus is the capability of the material to resist bending deformation within the elastic limit, and the bending strength and the bending modulus are both in units of MPa.

Method for testing coating bonding force

The plating adhesion refers to the bonding strength between the plating and the base resin or the intermediate plating, i.e., the force required to peel the plating per unit surface area from the base resin or the intermediate plating. The material was injection molded into 120 x 60 x 2mm square products, then electroplated and a10 x 80mm bar was cut on the plate surface with a knife. And (3) sticking the strip-shaped coating on the width of the strip-shaped coating by using 3M adhesive paper, and then testing the maximum force required when the coating is separated from the resin by using a universal testing machine, namely the coating binding force.

The raw materials used in the examples:

LCP: m400 of engineering plastic science and technology Limited of Deszhongtai, Jiangmen, the melting point of which is 320 ℃ and the thermal deformation temperature of which is 250 ℃;

PA 6: M2500I by Xinhui Mada Nylon Inc.;

PA 6T/66: d3000 of Delong-Teh engineering plastics science and technology Limited, Jiangmen;

PA 12T: t3000 resin of engineering plastic science and technology Limited of Deszhongtai, Jiangmen;

glass fiber: 301HP of international composite material for Chongqing;

carbon fiber: type-45 of east beauty of Japan;

silane coupling agent KH 550: a-1100 by Union, USA;

titanate coupling agent: KR-238S from Kenrich oil Co., USA;

TPE: g4774, Dupont, Inc., USA;

TPU: WHT-2195 of Nitzda Vanhua polyurethane GmbH;

TPO: CMV241 of exxonmobil chemical;

talc powder: italy Italian hair ratio HTP05L, 11000 mesh;

silicon dioxide: ST-O-001-2 from Tianjin Hongxin chemical reagent plant;

alumina: ALUna-100 of Guangzhou Jibisheng scientific and technical industries, Inc.

Example 1

A liquid crystal polymer composite for environment-friendly electroplating comprises the following raw materials (10 KG by weight):

the preparation method of the liquid crystal polymer composite for environment-friendly electroplating is characterized by comprising the following steps of:

(1) LCP and TPO are added into a double-screw extruder through a main feeder to carry out melt polymerization, and the mixture is obtained by bracing and granulating for later use;

(2) adding inorganic mineral powder talcum powder into a high-speed mixer, adding a silane coupling agent KH550 for reaction when the temperature of the inorganic mineral powder talcum powder is increased to 105 ℃, and taking out for later use, wherein the reaction time is 10 minutes;

(3) and (2) adding the blend obtained in the step (1) into a double-screw extruder through a main feeder, simultaneously adding the inorganic mineral powder talcum powder treated in the step (2) into a side feeder, mixing, performing melt extrusion at the temperature of 315 ℃, and granulating at the double-screw rotating speed of 300RMP to obtain the liquid crystal polymer composite.

Example 2

(1) LCP and TPU are added into a double-screw extruder through a main feeding machine for melt polymerization, and bracing and dicing are carried out to obtain a blend for later use;

(2) adding inorganic mineral powder alumina into a high-speed mixer, adding a silane coupling agent KH550 for reaction when the temperature of the inorganic mineral powder alumina is raised to 110 ℃, and taking out for later use, wherein the reaction time is 15 minutes;

(3) and (2) adding the blend obtained in the step (1) into a double-screw extruder through a main feeder, simultaneously adding the inorganic mineral powder alumina treated in the step (2) into a side feeder, mixing, performing melt extrusion at the temperature of 315 ℃, and granulating at the double-screw rotating speed of 300RMP to obtain the liquid crystal polymer composite.

Example 3

(1) LCP, PA6 and TPE are added into an internal mixer through a main feeder to carry out melt polymerization to obtain a blend for later use;

(2) adding inorganic mineral powder silicon oxide into a high-speed mixer, adding a silane coupling agent KH550 for reaction when the temperature of the inorganic mineral powder silicon oxide is raised to 105 ℃, and taking out for later use, wherein the reaction time is 20 minutes;

(3) and (2) adding the blend obtained in the step (1) into a double-screw extruder through a main feeder, simultaneously adding the inorganic mineral powder silicon oxide treated in the step (2) into a side feeder, mixing, performing melt extrusion at the temperature of 305 ℃, and granulating at the double-screw rotating speed of 300RMP to obtain the liquid crystal polymer composite.

Example 4

(2) adding inorganic mineral powder silicon oxide into a high-speed mixer, adding a coupling agent KH550 for reaction when the temperature of the inorganic mineral powder silicon oxide is raised to 120 ℃, and taking out for later use, wherein the reaction time is 25 minutes;

(3) and (2) adding the blend obtained in the step (1) into a double-screw extruder through a main feeder, simultaneously adding the inorganic mineral powder silicon oxide and the glass fiber 301HP which are processed in the step (2) into a side feeder, mixing, performing melt extrusion at the temperature of 305 ℃, and granulating at the rotating speed of the double screws of 300RMP to obtain the liquid crystal polymer composite.

Example 5

(1) LCP, PA6T/66 and TPO are added into a double-screw extruder through a main feeder to carry out melt polymerization, and the mixture is obtained by strand cutting and grain cutting for later use;

(2) adding inorganic mineral powder talcum powder into a high-speed mixer, adding a titanate coupling agent for reaction when the temperature of the inorganic mineral powder talcum powder is raised to 130 ℃, and taking out for later use, wherein the reaction time is 30 minutes;

(3) and (2) adding the blend obtained in the step (1) into a double-screw extruder through a main feeder, simultaneously adding the inorganic mineral powder talcum powder and the carbon fibers treated in the step (2) into a side feeder, mixing, performing melt extrusion at the temperature of 315 ℃, and granulating at the rotating speed of 300RMP of double screws to obtain the liquid crystal polymer composite.

Example 6

(1) LCP, PA12T and TPE are added into a double-screw extruder through a main feeder to carry out melt polymerization, and the mixture is obtained by strand cutting and granulation for later use;

(2) adding inorganic mineral powder talcum powder and alumina into a high-speed mixer, adding a titanate coupling agent for reaction when the temperature of the inorganic mineral powder talcum powder and the alumina rises to 130 ℃, and taking out for later use, wherein the reaction time is 315 minutes;

(3) and (2) adding the blend obtained in the step (1) into a double-screw extruder through a main feeder, simultaneously adding the inorganic mineral powder talcum powder and the alumina which are treated in the step (2) into a side feeder, mixing, performing melt extrusion at the temperature of 315 ℃, and performing granulation at the double-screw rotating speed of 300RMP to obtain the liquid crystal polymer compound.

Comparative example 1

The liquid crystal polymer composition comprises the following raw materials in percentage by weight

79% of liquid crystal polymer resin (LCP),

20 percent of inorganic mineral powder talcum powder,

and a silane coupling agent KH 5501%.

The preparation method of the liquid crystal polymer composition comprises the following steps:

(1) adding inorganic mineral powder talcum powder into a high-speed mixer, raising the temperature of the inorganic mineral powder talcum powder by 120 ℃, adding a silane coupling agent KH550 for reaction for 10 minutes, and taking out for later use;

(2) and (2) adding LCP into a double-screw extruder through a main feeder, simultaneously adding the inorganic mineral powder talcum powder treated in the step (1) into a side feeder, controlling the temperature to be 310 ℃ for melt extrusion, and granulating at the double-screw rotating speed of 300RMP to obtain the liquid crystal polymer composition.

Comparative example 2

(1) adding inorganic mineral powder silicon oxide into a high-speed mixer, raising the temperature of the inorganic mineral powder silicon oxide by 120 ℃, adding a titanate coupling agent for reaction for 10 minutes, and taking out for later use;

(2) and (2) adding LCP into a double-screw extruder through a main feeder, simultaneously adding the inorganic mineral powder silicon oxide and the glass fiber 301HP which are treated in the step (1) into a side feeder, carrying out melt extrusion at the temperature of 310 ℃, and carrying out granulation at the double-screw rotating speed of 300RMP to obtain the liquid crystal polymer composition.

The liquid crystal polymer compound obtained in examples 1 to 3 and comparative example 1 was subjected to plating after being treated with a potassium permanganate roughening solution, and a plating adhesion test was performed on a plating layer formed after plating. The liquid crystal polymer composites obtained in examples 4 to 6 and comparative example 2 were subjected to a plating process after a treatment with a chromic acid roughening solution, and a plating adhesion test was performed on the plating layer formed after the plating process. The test results are shown in table 1.

The liquid-crystalline polymer composites obtained in examples 1 to 6 and comparative examples 1 to 2 were tested for their physical and mechanical properties, and the results were shown in

Shown in table 2.

TABLE 1 test of plating adhesion of liquid crystal polymer composites obtained in examples 1 to 6 and comparative examples 1 to 2

TABLE 2 Properties of liquid-crystalline polymer composites obtained in examples 1 to 6 and comparative examples 1 to 2

Claims

1. The liquid crystal polymer composite for environment-friendly electroplating is characterized by comprising the following raw materials in percentage by weight:

wherein the sum of the raw materials is 100 percent;

wherein the thermoplastic elastomer has a melt index higher than that of the liquid crystalline polymer; the liquid crystal polymer is aromatic copolyester, the melting point of the liquid crystal polymer is lower than 330 ℃, and the thermal deformation temperature of the liquid crystal polymer is higher than 200 ℃;

the liquid crystal polymer composite for environment-friendly electroplating is prepared by the following steps:

(1) mixing a liquid crystal polymer, polyamide resin and a thermoplastic elastomer, and reacting in a high-pressure reaction kettle, an internal mixer or an extruder to obtain a blend for later use;

2. The liquid crystal polymer composite for eco-friendly plating according to claim 1, wherein the polyamide resin is at least one of an aromatic polyamide resin, a semi-aromatic polyamide resin and an aliphatic polyamide resin.

3. Liquid crystal polymer composite for eco-friendly electro-plating according to claim 1 or 2, characterised in that the polyamide is selected from at least one of PA6, PA46, PA66, PA6T/66, PA6T/6I, PA612, PA11, PA12, PA9T, PA10T, PA12T, MAXD 6.

4. The liquid crystal polymer composite for eco-friendly plating according to claim 1, wherein the thermoplastic elastomer is at least one of polyolefin elastomer, polyester elastomer and polystyrene elastomer.

5. The liquid crystalline polymer composite for eco-friendly plating according to claim 1, wherein the thermoplastic elastomer has a melt index > 2g/10min, test conditions: 220 ℃ and 2.16 kg.

6. The liquid crystal polymer composite for environmental protection electroplating according to claim 1, wherein the inorganic mineral powder is at least one of talcum powder, aluminum oxide, silicon oxide, zinc oxide and montmorillonite.

7. The liquid crystal polymer composite for environment-friendly electroplating according to claim 1 or 6, wherein the inorganic mineral powder is modified by a coupling agent.

8. The liquid crystal polymer composite for eco-friendly plating according to claim 1, further comprising one or more of a fiber reinforcement, a color masterbatch, a nucleating agent and an antioxidant.

9. The method for preparing a liquid crystal polymer composite for eco-friendly plating according to any one of claims 1 to 8, comprising the steps of: