CN114369287B

CN114369287B - Laser foaming auxiliary agent composition and preparation method and application thereof

Info

Publication number: CN114369287B
Application number: CN202111621238.2A
Authority: CN
Inventors: 贾礼洋; 郭华; 王磊; 邓明; 黄明路; 高原; 王大林
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2023-09-19
Anticipated expiration: 2041-12-28
Also published as: CN114369287A

Abstract

The invention discloses a laser foaming auxiliary agent composition, a preparation method and application thereof, wherein the composition comprises boron nitride, graphene oxide, a coupling agent and a thermoplastic polymer, and the mass ratio of the boron nitride to the graphene oxide to the coupling agent to the thermoplastic polymer is 1: (1-15): (0.05-0.3): (1-30). After the laser foaming auxiliary agent composition is added into various colored polymer materials, the dispersibility of the laser foaming auxiliary agent in the polymer materials is greatly improved, the obvious laser foaming effect is realized, and the colored polymer foaming material with uniform cell structure is obtained. The preparation method of the laser foaming auxiliary agent disclosed by the invention is simple and efficient, can be suitable for polymer materials (including thermoplastic polymers and thermosetting polymers) with different colors, has a wide application prospect, and is very suitable for mass production.

Description

Laser foaming auxiliary agent composition and preparation method and application thereof

Technical Field

The invention belongs to the field of polymer material additives and material processing, and particularly relates to a laser foaming additive composition, a preparation method and application thereof.

Background

The laser foaming is a novel foaming technology for realizing the local foaming of a material by irradiating the surface of the material with high energy of laser to cause a series of complex photochemical and/or photo-thermal reactions. Compared with the traditional foaming technology, the technology has the advantages of simple process, environmental friendliness, low cost, local controllability and the like, and can accurately trigger foaming in a certain area of the material.

Because most polymeric materials (e.g., polypropylene, ethylene-octene copolymers, cyclic olefin copolymers, etc.) have insufficient ability to absorb laser energy, laser irradiation has difficulty in directly achieving surface foaming of the polymeric material. The existing method is to add specific additives (also called auxiliaries) to polymer materials to prepare laser-induced polymer foam materials.

Chinese patent CN102939330B discloses a laser-induced polymer foam material comprising a polymer, a laser absorber and a foaming agent. However, it adopts metal flakes, metal oxides, metal phosphates, etc. as laser absorber materials, which not only increases raw material costs and manufacturing costs, but also causes environmental pollution and affects personnel health when contacting the laser absorber for a long time. In addition, due to the existence of the foaming agent, the processing temperature needs to be strictly controlled and/or other additives are additionally added in the production process, so that the premature reaction of the foaming agent is prevented or delayed, and the defects of complicated control process, high energy consumption and the like exist.

Chinese patent CN108841031B discloses the application of graphene as a laser foaming agent, in which a single graphene is directly added to a thermoplastic polymer material, so that a better laser foaming effect can be achieved under laser irradiation, but a better laser foaming effect cannot be obtained for thermosetting resin. On the other hand, the graphene is black or dark gray in color and has strong dyeing capability, when the graphene is added into the polymer material, the bottom color of the polymer material can be obviously changed to be black, gray black or dark gray, so that single graphene can only be applied to the black or dark polymer material to realize laser foaming of the polymer material, and the laser foaming of the polymer material with different colors cannot be met, so that the application field of the polymer material is severely limited, and the industrialization is limited.

Chinese patent CN106633764a discloses a laser marking additive composed of graphene and a polymer, which improves the dispersion effect of graphene powder in a laser marking object, but only can realize laser marking of the polymer after laser irradiation, and still cannot induce laser foaming of the polymer.

Therefore, there is a need in the art to develop a novel auxiliary agent for laser foaming, which can absorb laser and generate gas when irradiated by laser, so that the auxiliary agent can be used for thermoplastic and thermosetting various polymers, and can perform laser foaming on the surfaces of the polymer materials with various colors, thereby meeting the requirements of industry on products with various colors.

Disclosure of Invention

In order to solve the problems, the invention aims to provide a laser foaming auxiliary agent composition which can be used for various thermoplastic and thermosetting polymers and can rapidly realize laser foaming of polymer materials with different colors under the irradiation of laser. The invention also aims at providing a preparation method and application of the auxiliary agent composition.

The invention provides a laser foaming auxiliary agent composition, which comprises boron nitride, graphene oxide, a coupling agent and a thermoplastic polymer;

the mass ratio of the boron nitride to the graphene oxide to the coupling agent to the thermoplastic polymer is 1: (1-15): (0.05-0.3): (1-30); preferably 1: (1-10): (0.05-0.2): (1-15).

In the invention, the boron nitride is a nano particle with a lamellar structure;

preferably, the average platelet diameter in the boron nitride particles is 90 μm or less, preferably 60 μm or less, more preferably 9 to 15 μm;

the number of the lamellar layers of the boron nitride particles is preferably 200 or less, more preferably 125 or less, and still more preferably 13 to 90.

In the invention, the graphene oxide is a nano particle with a lamellar structure;

preferably, the average platelet diameter in the graphene oxide particles is 90 μm or less, preferably 60 μm or less, more preferably 8 to 16 μm;

The number of lamellar layers of the graphene oxide particles is preferably 80 or less, more preferably 50 or less, and still more preferably 5 to 39.

The graphene oxide is a nano two-dimensional material, and the experiment shows that the graphene oxide with smaller lamellar diameter can form a stronger network structure and stronger interface interaction in the polymer, so that the dispersibility of the graphene oxide is improved; meanwhile, the graphene oxide can have higher absorbance through the selection of the number of layers and the particle thickness, and the laser absorption capacity of the material can be improved. Based on the method, the graphene oxide with the specific range of the lamellar diameter and lamellar number is selected, so that the good dispersing effect of the graphene oxide in the polymer is ensured, and meanwhile, the high laser absorption capacity is realized.

According to the invention, in experiments, the combination of the graphene oxide and the boron nitride according to a specific proportion has a synergistic effect on improving the laser foaming effect of the polymer material, besides the influence of the chemical composition of the boron nitride, the boron nitride is used as a nano two-dimensional material, the diameter of a slice layer and the thickness of the slice layer also have a remarkable influence on the laser foaming effect, and the boron nitride with the similar size to the graphene oxide is selected, so that the boron nitride and the graphene oxide have better dispersion effect and laser absorption capability in the polymer. The graphene oxide and the boron nitride are cooperatively used, so that the graphene oxide and the boron nitride can be used as a laser absorber to absorb laser, and unexpected findings can be used as a foaming agent to generate gas, so that the surface of the polymer is quickly foamed under the induction of the laser, and the foaming effect is improved.

Preferably, the oxygen content of the graphene oxide is 25 to 55wt%, preferably 35 to 55wt%. The oxygen content of graphene oxide, which represents the number of oxygen-containing functional groups on its surface, affects the laser foaming effect. After laser irradiation, the graphene oxide can convert the absorbed laser energy into instantaneous high temperature, so that oxygen-containing functional groups on the surface of the graphene oxide undergo a cracking or decomposition reaction, thereby releasing gas and inducing the surface of the polymer material to foam. However, in order to achieve the foaming effect, the oxygen content of the graphene oxide needs to be limited to a specific range, and when the oxygen content is less than 25wt%, the gas generated by the oxygen-containing functional groups on the surface of the graphene oxide is insufficient to induce foaming of the polymer material after the laser irradiation; when the oxygen content is higher than 55wt%, after laser irradiation, the oxygen functional groups on the surface of the graphene oxide generate excessive gas, so that more larger pores can be formed in the material, and meanwhile, the phenomena of cell merging, cracking, collapse and the like occur, so that the foaming effect is seriously affected.

In the invention, the coupling agent is selected from one or more of fatty acid, silane coupling agent, titanate coupling agent, zirconate coupling agent and phosphate coupling agent, preferably the silane coupling agent is more preferably one or more of A-151, KH-550, KH-560, KH-570, KH-580 and Z-6030.

In the present invention, the thermoplastic polymer is selected from a polymer material having an aromatic ring or an alicyclic structure, preferably any one or more of polyethylene terephthalate, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene copolymer, styrene-acrylonitrile copolymer, polybutylene terephthalate, aromatic polyamide, polyphenylene oxide, polyimide, polysulfone, and polyether ether ketone.

The polymer material with the molecular chain containing aromatic rings such as benzene rings or alicyclic ring structures has good thermal stability, the polymer is not easy to be thermally decomposed at the instant high temperature generated after laser irradiation, and meanwhile, the ring structures such as benzene rings in the polymer molecular chain can also form pi-pi conjugated effect with graphene oxide, so that the dispersion effect of the graphene oxide is improved, and the re-agglomeration of the graphene oxide in the processing process is inhibited.

The invention also provides a preparation method of the laser foaming auxiliary agent composition, which comprises the following steps:

1) Dissolving a thermoplastic polymer in an organic solvent to obtain a thermoplastic polymer solution;

2) Uniformly mixing graphene oxide and boron nitride, adding the mixture into an alcohol solvent, and performing ultrasonic treatment on the mixture to obtain graphene oxide/boron nitride dispersion liquid;

3) Adding a coupling agent into the water/alcohol mixed solution for prehydrolysis, and then uniformly mixing the coupling agent with the graphene oxide/boron nitride dispersion liquid obtained in the step 2) to obtain a dispersion mixed liquid;

4) And (3) dropwise adding the polymer solution obtained in the step (1) into the dispersion mixed solution obtained in the step (3) under stirring, and after the dropwise adding is finished, precipitating, filtering and drying to obtain the laser foaming auxiliary agent.

In the preparation method, in the step 1), the concentration of the thermoplastic polymer dissolved in the organic solvent is 1 g/(1-500) mL, preferably 1 g/(10-200) mL;

preferably, the organic solvent is any one or more of benzene, toluene, xylene, chlorobenzene, dichloromethane, chloroform, N-dimethylformamide, dimethyl sulfoxide, acetone, tetrahydrofuran, cyclohexane and N-hexane.

In the preparation method, in the step 2), the dispersion concentration of the graphene oxide and the boron nitride in the alcohol solvent is 1 g/(10-1000) mL, preferably 1 g/(10-100) mL, based on the total mass of the graphene oxide and the boron nitride;

preferably, the alcohol solvent is any one or more of ethanol, methanol, propanol and isopropanol;

the ultrasonic treatment is carried out, and the ultrasonic power is 100-1500W, preferably 500-1300W; the ultrasonic treatment time is 5-18 hours, preferably 5-15 hours.

In the preparation method, in the step 3), the concentration of the coupling agent added into the water/alcohol mixed solution is 1 g/(160-1000 mL), preferably 1 g/(260-842 mL);

preferably, in the mixed solution of water and alcohol, the volume ratio of water (preferably deionized water) to alcohol is 0.5-2: 50; preferably, the alcohol is any one or more of ethanol, methanol, propanol and isopropanol;

the prehydrolysis is carried out at a temperature of 25-100 ℃, preferably 25-60 ℃; the time is 0.5 to 3 hours, preferably 1.5 to 3 hours.

In the preparation method, in the step 4), the stirring and dripping are conventional in the field, the preparation method has no specific requirement, and preferably, the stirring speed is more than or equal to 100r/min.

The preparation method of the invention, step 4), also include precipitating, filtering, drying, etc. process, for the field conventional operation, the invention does not have specific requirements, the solid after drying is preferably crushed into powder with granularity of 0.5-35 mu m, namely the said laser foaming auxiliary agent.

The invention also provides application of the laser foaming auxiliary agent composition in preparing a laser foaming material.

Preferably, the present invention provides a laser-foamed polymeric material comprising a colored polymeric substrate material and a laser-foaming aid composition;

Preferably, the laser foaming auxiliary composition is 5-45% of the mass of the color polymer substrate material, more preferably 25-45%;

the laser foaming polymer material can be prepared by the following method:

s1: adding the laser foaming auxiliary agent composition into a color polymer substrate material, and performing injection molding or curing molding;

s2: and (3) performing laser-induced foaming on the S1 molding material to obtain the laser foaming polymer material.

In the above method S1, the injection molding or the curing molding is a molding method known in the prior art, and a skilled person can select a suitable molding method according to the characteristics of the polymer base material, which is not particularly required in the present invention. The injection molding temperature of the different polymers varies, and is usually controlled to be 30-50 ℃ higher than the melting point of the polymers, preferably 170-300 ℃ in S2.

In the above method S2, the conditions of the laser induced foaming are:

the laser wavelength is 193 nm-10.6 μm, preferably near infrared laser (1064 nm, 808 nm), nd: one of YAG laser (532 nm) and CO2 laser (10.6 μm);

the laser scanning speed is 100-2000 mm/s, preferably 1000-2000 mm/s; the laser energy is 5 to 30W, preferably 8 to 20W.

Because different laser transmitters have differences in scanning speed and laser energy, the conditions for preparing the laser foaming material can be adjusted according to actual needs, and the conditions for preparing the laser foaming material only need to induce the polymer to foam.

In the present invention, the term "color" refers to a single common color such as red, blue, orange, yellow, green, purple, or various mixed colors of the above colors. It should be noted that the colors of black, gray-black, gray, white, light white, etc. do not fall within the scope of the color defined in the present invention.

In the present invention, the colored polymer base material means a polymer material to which colorants of different colors are added and which is prepared by extrusion blending, which is well known in the art. The polymer material includes thermoplastic polymer material and thermosetting polymer material; the thermoplastic polymer material is selected from any one or more of low-density polyethylene, high-density polyethylene, polypropylene, cycloolefin copolymer, ethylene-octene copolymer, ethylene-butene copolymer, polycarbonate, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer, thermoplastic polyurethane elastomer, polystyrene, styrene-butadiene-styrene block copolymer, polyamide, polyoxymethylene, polyethylene terephthalate, polybutylene terephthalate, polylactic acid and poly adipic acid/butylene terephthalate; the thermosetting polymer material is selected from any one or more of epoxy resin, phenolic resin, urea resin, unsaturated polyester and melamine-formaldehyde resin, but is not limited to the above.

The invention provides a novel and efficient laser foaming auxiliary agent composition, which is prepared from graphene oxide, boron nitride, a coupling agent and a thermoplastic polymer in a specific proportion, and has an excellent foaming effect. The auxiliary agent can realize laser foaming on various polymer materials with different colors, the foam cell structure of a foaming area is also very uniform, a new technical approach is provided for preparing the foaming of the laser-induced color polymer material, and the application fields of boron nitride and graphene oxide and the universality of the laser foaming technology on various polymer materials (including thermoplastic polymers and thermosetting polymers) are widened.

The preparation method of the laser foaming auxiliary agent disclosed by the invention is simple and efficient, is suitable for polymer materials with different colors, has very good economic benefit, and is very easy to apply in industrialization. The thermoplastic polymer containing the aromatic ring or the alicyclic ring structure not only can improve the compatibility of the laser foaming auxiliary agent and the matrix material and promote the dispersion effect of the auxiliary agent, but also can enhance the melt strength of the matrix material, and is beneficial to maintaining the gas generated in the foaming process, thereby forming the foaming material with uniform cell structure.

Compared with the prior art, the technical scheme of the invention has the beneficial effects that:

(1) The invention combines graphene oxide and boron nitride, not only can be used as a laser absorber to absorb laser, but also can be used as a foaming agent to generate the foaming effect of the gas reinforced polymer material. When the graphene oxide and the boron nitride are irradiated by laser, the absorbed laser energy can be converted into instantaneous high temperature, and the gas quantity generated in the laser foaming process is controlled according to different oxygen contents of the graphene oxide, so that the foaming effect is regulated and controlled. In addition, higher melt strength is critical to foaming, and an increase in melt strength helps to maintain the gas produced, and thus to stabilize the cell structure during the cell growth stage, thereby forming a foamed material having a uniform cell structure. In addition, the graphene oxide and the boron nitride also have a nucleating agent effect on the polymer, and the crystallization speed of the polymer is improved, so that the crystallinity of the polymer is increased, and the crystal structure is used as a physical crosslinking point in the matrix material, so that the melt strength of the matrix material is enhanced.

(2) The laser foaming auxiliary agent composition provided by the invention also solves the defect of common laser foaming effect of thermosetting resin, and the laser foaming auxiliary agent prepared by the invention can obtain better laser foaming effect when being added into epoxy resin (thermosetting resin). The oxygen-containing functional groups rich in the surface of the graphene oxide can form stable chemical bonds with the epoxy resin, so that the graphene oxide can form good dispersion in the epoxy resin, and has good interface effect with an epoxy resin matrix, thereby improving the laser absorption capacity of the epoxy resin and further realizing good laser foaming effect of the thermosetting resin.

(3) The laser foaming auxiliary agent composition provided by the invention can realize laser foaming on various polymer materials with different colors, and provides a new technical approach for preparing foaming of the laser-inducible colored polymer materials.

Detailed Description

The above-described aspects of the present invention will be described in further detail below with reference to specific embodiments in the form of examples. It should not be construed that the scope of the above subject matter of the present invention is limited to the following examples. It should be apparent that, in light of the foregoing, various modifications, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. All techniques implemented based on the above description of the invention are within the scope of the invention.

The materials and equipment used in the embodiments of the present invention are all known products and are obtained by purchasing commercially available products.

Wherein, partial raw materials sources are as follows:

graphene oxide: nano, powdery in the middle age;

boron nitride: powdered form of Suzhou Napoy materials technologies Co., ltd;

polystyrene (PS): yang Ziba Schiff, GPPS-165H;

Polycarbonate (PC): korean three stars, SC-1220R;

acrylonitrile-butadiene-styrene copolymer (ABS): taiwan qi mei, PA747;

polybutylene terephthalate (PBT) DuPont, U.S. DuPont, S650FR;

polypropylene (PP): china petrochemical England company, T30S;

high Density Polyethylene (HDPE): luxuriant petrochemical industry, TR144;

cycloolefin copolymer (COC): a japanese pulsatilla, 1410R;

ethylene-octene copolymer (POE): us dow, 8100;

epoxy resin (bisphenol a type epoxy resin): kjew chemistry, E51;

curing agent (low molecular weight polyamide): yi contains chemical industry Co.Ltd., 651.

Example 1

(1) Preparation of a laser foaming aid composition:

1) 10g of polystyrene was dissolved in 100mL of toluene to obtain a polystyrene toluene solution;

2) Uniformly mixing 9g of graphene oxide (with an average lamellar diameter of 8 mu m, lamellar number of 5 layers and oxygen content of 25 wt%) and 1g of boron nitride (with an average lamellar diameter of 10 mu m and lamellar number of 15 layers), dispersing in 100mL of ethanol, and performing ultrasonic treatment for 18h (with ultrasonic power of 1300W) to obtain graphene oxide/boron nitride ethanol dispersion liquid;

3) Adding 0.2g KH-550 into a mixed solution of 2mL deionized water and 50mL ethanol for prehydrolysis for 3h at the prehydrolysis temperature of 25 ℃, and uniformly mixing the mixed solution with graphene oxide/boron nitride ethanol dispersion liquid to obtain a dispersion mixed liquid;

4) And (3) dropwise adding the polystyrene toluene solution into the dispersion mixed solution, continuously stirring, controlling the stirring speed to be 500r/min until the dropwise adding is completed, precipitating, filtering, drying and crushing to obtain the laser foaming auxiliary composition.

(2) Preparation of a laser foaming thermoplastic polymer material:

1) Adding the obtained laser foaming auxiliary composition into polypropylene (PP) in an amount of 5wt%, adding pigment red 176 (organic red) in an amount of 1.2wt%, blending and extruding by a double-screw extruder, and granulating; and directly injection molding the mixed red granules in an injection molding machine to prepare a standard template with red base color, wherein the temperature in the processing process is controlled at 190-240 ℃.

The standard template was subjected to laser induced foaming using the following conditions: the pulse near infrared laser has a laser wavelength of 1064nm, a scanning speed of 2000mm/s, a laser energy of 8W, a laser frequency of 20KHz, and a foaming effect shown in Table 1.

(3) Preparation of laser foaming thermosetting polymer material:

the laser foaming auxiliary composition obtained in (1) was added to an epoxy resin at 5wt% while adding a curing agent (low molecular weight polyamide, 651) at 25wt% and pigment blue 36 (inorganic blue) at 1.0wt%, and the mixture was sufficiently and uniformly mixed in a mixer, and cured for 4 days at 55℃to prepare an epoxy resin standard template having a blue base color.

The standard template was subjected to laser induced foaming using the following conditions: the pulse near infrared laser has a laser wavelength of 1064nm, a scanning speed of 2000mm/s, a laser energy of 10W, a laser frequency of 20KHz, and a foaming effect shown in Table 1.

Example 2

(1) Preparation of a laser foaming aid composition:

1) 0.5g of polycarbonate was dissolved in 100mL of methylene chloride to obtain a methylene chloride solution of polycarbonate;

2) Uniformly mixing 7.5g of graphene oxide (with an average lamellar diameter of 16 mu m, lamellar layers of 39 layers and an oxygen content of 30 wt%) and 0.5g of boron nitride (with an average lamellar diameter of 15 mu m and lamellar layers of 90 layers), dispersing in 100mL of ethanol, and carrying out ultrasonic treatment for 15h (with ultrasonic power of 1500W) to obtain graphene oxide/boron nitride ethanol dispersion liquid;

3) Adding 0.15g KH-570 into a mixed solution of 1.5mL deionized water and 50mL ethanol for prehydrolysis for 2.5h at the prehydrolysis temperature of 45 ℃, and uniformly mixing the mixed solution with graphene oxide/boron nitride ethanol dispersion liquid to obtain a dispersion mixed liquid;

4) And (3) dropwise adding the polycarbonate methylene dichloride solution into the dispersion mixed solution, continuously stirring, controlling the stirring speed to be 200r/min until the dropwise adding is completed, precipitating, filtering, drying and crushing to obtain the laser foaming auxiliary composition.

(2) Preparation of laser foaming thermosetting polymer material:

1) The obtained laser foaming auxiliary composition was added to an epoxy resin at 25wt%, and at the same time, 25wt% of a curing agent (low molecular weight polyamide, 651) and 1.0wt% of pigment blue 36 (inorganic blue) were added, and the mixture was sufficiently and uniformly mixed in a mixer, and the mixture was heated to 55℃and cured for 4 days to prepare an epoxy resin standard template having a blue base color.

The standard template was subjected to laser induced foaming using the following conditions: the pulse near infrared laser has laser wavelength of 1064nm, scanning speed of 1000mm/s, laser energy of 20W, laser frequency of 30KHz, and foaming effect shown in Table 1.

Example 3

(1) Preparation of a laser foaming aid composition:

1) 15g of polycarbonate was dissolved in 30mL of methylene chloride to obtain a methylene chloride solution of polycarbonate;

2) Uniformly mixing 5g of graphene oxide (with an average lamellar diameter of 15 mu m, lamellar number of 45 layers and oxygen content of 35 wt%) and 1g of boron nitride (with an average lamellar diameter of 12 mu m and lamellar number of 113 layers), dispersing in 100mL of ethanol, and carrying out ultrasonic treatment for 15 hours (with ultrasonic power of 800W) to obtain graphene oxide/boron nitride ethanol dispersion liquid;

3) Adding 0.05g KH-560 into a mixed solution of 1mL deionized water/25 mL ethanol for prehydrolysis for 1.5h at a prehydrolysis temperature of 60 ℃, and then uniformly mixing the mixed solution with graphene oxide/boron nitride ethanol dispersion liquid to obtain a dispersion mixed liquid;

4) And (3) dropwise adding the polycarbonate methylene dichloride solution into the dispersion mixed solution, continuously stirring, controlling the stirring speed to be 1000r/min until the dropwise adding is completed, precipitating, filtering, drying and crushing to obtain the laser foaming auxiliary composition.

(2) Preparation of laser foaming thermosetting polymer material:

1) The obtained laser foaming auxiliary composition was added to an epoxy resin at 30wt%, and at the same time, 25wt% of a curing agent (low molecular weight polyamide, 651) and 1.2wt% of pigment red 176 (organic red) were added, and the mixture was sufficiently and uniformly mixed in a mixer, and the mixture was heated to 55℃and cured for 4 days to prepare an epoxy resin standard template having a red base color.

The standard template was subjected to laser induced foaming using the following conditions: CO ₂ The laser wavelength is 10.6 μm, the scanning speed is 1500mm/s, the laser energy is 15W, the laser frequency is 50KHz, and the foaming effect is shown in Table 1.

Example 4

(1) Preparation of a laser foaming aid composition:

1) 7.5g PET was dissolved in 100mL methylene chloride to give a PET/methylene chloride solution;

2) Uniformly mixing 2.5g of graphene oxide (with an average lamellar diameter of 10 mu m, lamellar layers of 8 layers and an oxygen content of 40 wt%) and 0.25g of boron nitride (with an average lamellar diameter of 9 mu m and lamellar layers of 13 layers), dispersing in 100mL of ethanol, and carrying out ultrasonic treatment for 10 hours (with ultrasonic power of 1000W) to obtain graphene oxide/boron nitride ethanol dispersion liquid;

3) Adding 0.051g KH-550 into a mixed solution of 0.5mL deionized water and 50mL ethanol for prehydrolysis for 1.5h at a prehydrolysis temperature of 25 ℃, and uniformly mixing the mixed solution with graphene oxide/boron nitride ethanol dispersion to obtain a dispersion mixed solution;

4) And (3) dropwise adding the PET/dichloromethane solution into the dispersion mixed solution, controlling the stirring speed at 300r/min, continuously stirring until the dropwise adding is completed, precipitating, filtering, drying and crushing to obtain the laser foaming auxiliary composition.

(2) Preparation of a laser foaming thermoplastic polymer material:

1) Adding 35wt% of the obtained laser foaming auxiliary composition into cycloolefin copolymer (COC), adding 1.5wt% of pigment yellow 62 (organic yellow), adopting a double-screw extruder to blend and extrude, and granulating; and directly injection molding the obtained mixed yellow granules in an injection molding machine to prepare a standard template with yellow base color, wherein the temperature in the processing process is controlled between 245 and 300 ℃.

The standard template was subjected to laser induced foaming using the following conditions: the pulse near infrared laser has the laser wavelength of 808nm, the scanning speed of 1000mm/s, the laser energy of 15W, the laser frequency of 20KHz and the foaming effect shown in Table 1.

Example 5

(1) Preparation of a laser foaming aid composition:

1) 0.2g of polysulfone is dissolved in 100mL of dimethyl sulfoxide to obtain a polysulfone dimethyl sulfoxide solution;

2) Uniformly mixing 0.8g of graphene oxide (with an average lamellar diameter of 86 mu m, a lamellar layer number of 65 layers and an oxygen content of 50 wt%) and 0.2g of boron nitride (with an average lamellar diameter of 85 mu m and a lamellar layer number of 190 layers), dispersing in 100mL of ethanol, and carrying out ultrasonic treatment for 5h (with ultrasonic power of 1300W) to obtain graphene oxide/boron nitride ethanol dispersion liquid;

3) Adding 0.06-g A to 151 into a mixed solution of 0.5mL of deionized water and 50mL of ethanol, prehydrolyzing for 2.5h at the prehydrolysis temperature of 60 ℃, and uniformly mixing the solution with graphene oxide/boron nitride ethanol dispersion to obtain a dispersion mixed solution;

4) And (3) dropwise adding the polysulfone dimethyl sulfoxide solution into the dispersion mixed solution, controlling the stirring speed at 100r/min, continuously stirring until the dropwise adding is completed, precipitating, filtering, drying and crushing to obtain the laser foaming auxiliary composition.

(2) Preparation of a laser foaming thermoplastic polymer material:

1) Adding 40wt% of the obtained laser foaming auxiliary composition into acrylonitrile-butadiene-styrene copolymer (ABS), adding 1.0wt% of pigment green 7 (organic green), adopting a double-screw extruder to blend and extrude, and granulating; the obtained mixed green granules are directly injection molded in an injection molding machine to prepare a standard template with green base color, and the temperature in the processing process is controlled between 185 ℃ and 240 ℃.

The standard template was subjected to laser induced foaming using the following conditions: the pulse near infrared laser has laser wavelength of 1064nm, scanning speed of 800mm/s, laser energy of 25W, laser frequency of 40KHz, and foaming effect shown in Table 1.

Example 6

(1) Preparation of a laser foaming aid composition:

1) 0.3g of PET was dissolved in 30mL of methylene chloride to obtain a PET/methylene chloride solution;

2) Uniformly mixing 0.05g of graphene oxide (with an average lamellar diameter of 85 mu m, lamellar layers of 75 layers and an oxygen content of 55 wt%) and 0.05g of boron nitride (with an average lamellar diameter of 83 mu m and lamellar layers of 190 layers), dispersing in 100mL of ethanol, and carrying out ultrasonic treatment for 15h (with ultrasonic power of 100W) to obtain graphene oxide/boron nitride ethanol dispersion liquid;

3) Adding 0.015g KH-570 into a mixed solution of 0.5mL deionized water and 12.5mL ethanol to pre-hydrolyze for 0.5h at a temperature of 100 ℃, and uniformly mixing the mixed solution with the graphene oxide/boron nitride ethanol dispersion to obtain a dispersion mixed solution;

4) And (3) dropwise adding the PET/dichloromethane solution into the dispersion mixed solution, controlling the stirring speed at 350r/min, continuously stirring until the dropwise adding is completed, precipitating, filtering, drying and crushing to obtain the laser foaming auxiliary composition.

(2) Preparation of a laser foaming thermoplastic polymer material:

1) Adding 45wt% of the obtained laser foaming auxiliary composition into high-density polyethylene (HDPE), simultaneously adding 1.1wt% of pigment orange 34 (organic orange), adopting a double-screw extruder to blend and extrude, and granulating; the obtained orange granules after mixing are directly injection molded in an injection molding machine to prepare a standard template with orange base color, and the temperature in the processing process is controlled between 190 and 240 ℃.

The standard template was subjected to laser induced foaming using the following conditions: CO ₂ The laser wavelength is 10.6 μm, the scanning speed is 1200mm/s, the laser energy is 30W, the laser frequency is 80KHz, and the foaming effect is shown in Table 1.

Example 7

(1) Preparation of a laser foaming aid composition:

1) 30g of polystyrene was dissolved in 30mL of toluene to obtain a polystyrene toluene solution;

2) Uniformly mixing 2g of graphene oxide (the average lamellar diameter is 55 mu m, the lamellar layer number is 70 layers, the oxygen content is 45 wt%) and 2g of boron nitride (the average lamellar diameter is 55 mu m, the lamellar layer number is 188 layers), dispersing in 100mL of ethanol, and carrying out ultrasonic treatment for 15h (the ultrasonic power is 500W) to obtain graphene oxide/boron nitride ethanol dispersion liquid;

3) Adding 0.32-g A-51 into a mixed solution of 1.2mL of deionized water and 50mL of ethanol for prehydrolysis for 3 hours, wherein the prehydrolysis temperature is 60 ℃, and then uniformly mixing the solution with graphene oxide/boron nitride ethanol dispersion liquid to obtain a dispersion mixed liquid;

4) And (3) dropwise adding the polystyrene toluene solution into the dispersion mixed solution, controlling the stirring speed at 1500r/min, continuously stirring until the dropwise adding is completed, precipitating, filtering, drying and crushing to obtain the laser foaming auxiliary composition.

(2) Preparation of a laser foaming thermoplastic polymer material:

1) Adding 35wt% of the obtained laser foaming auxiliary composition into ethylene-octene copolymer (POE), adding 1.2wt% of pigment blue 36 (inorganic blue), adopting a double-screw extruder to blend and extrude, and granulating; and directly injection molding the obtained mixed blue granules in an injection molding machine to prepare a standard template with blue base color, wherein the temperature in the processing process is controlled at 170-230 ℃.

The standard template was subjected to laser induced foaming using the following conditions: nd: YAG laser with laser wavelength of 532nm, scanning speed of 100mm/s, laser energy of 5W, laser frequency of 10KHz, and foaming effect shown in Table 1.

Comparative example 1

A laser foaming aid composition was prepared by the method of reference example 1, except that: boron nitride is not added, and other conditions are unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 2

A laser foaming aid composition was prepared by the method of reference example 1, except that: graphene oxide is not added, and other conditions are unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 3

A laser foaming aid composition was prepared by the method of reference example 1, except that: without the addition of thermoplastic polymer (polystyrene), the other conditions are unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 4

A laser foaming aid composition was prepared according to the method of example 1, except that: the graphene oxide is replaced by equal-mass graphene, and other conditions are unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 5

A laser foaming aid composition was prepared according to the method of example 1, except that: the thermoplastic polymer is replaced by an equal mass thermosetting polymer (phenolic resin) with the other conditions unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 6

A laser foaming aid composition was prepared according to the method of example 1, except that: the thermoplastic polymer is replaced by an equal mass low density polyethylene, the other conditions being unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 7

A laser foaming aid composition was prepared according to the method of example 1, except that: the boron nitride is replaced by aluminum nitride, and other conditions are unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 8

A laser foaming aid composition was prepared according to the method of example 1, except that: the raw material ratio for preparing the laser foaming auxiliary agent composition is replaced by boron nitride, graphene oxide, a coupling agent and a thermoplastic polymer, and the mass ratio is 1:0.75:0.025:0.05, the other conditions being unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 9

A laser foaming aid composition was prepared according to the method of example 1, except that: the average platelet diameter of boron nitride was replaced with 100 μm, with the other conditions unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 10

A laser foaming aid composition was prepared according to the method of example 1, except that: the number of the boron nitride layers is replaced by 225 layers, and other conditions are unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 11

A laser foaming aid composition was prepared according to the method of example 1, except that: the average platelet diameter of graphene oxide was replaced with 100 μm, with the other conditions unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 12

A laser foaming aid composition was prepared according to the method of example 1, except that: the number of the graphene oxide layers is replaced by 90 layers, and other conditions are unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 13

A laser foaming aid composition was prepared according to the method of example 1, except that: the oxygen content of graphene oxide was replaced with 65wt% with the other conditions unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Comparative example 14

A laser foaming aid composition was prepared according to the method of example 1, except that: the oxygen content of graphene oxide was replaced with 15wt% with the other conditions unchanged. The foaming aids prepared were then used for thermoplastic polymer and thermosetting polymer laser foaming materials, respectively, in the manner of example 1, the foaming effect being shown in Table 1.

Laser foaming aid formulation compositions of examples 1 to 7 and comparative examples 1 to 14 and foaming effect test method:

1. evaluation of laser foaming Effect

In the evaluation of the laser foaming effect, the greater the number of "+" means that the better the laser foaming effect.

2. Experimental results

The vertical distance from the highest point of the foam of the polymer material after laser foaming to the surface of the substrate is defined as the foaming height, and the numerical value is measured by a vernier caliper.

And (3) carrying out liquid nitrogen brittle fracture on the polymer material after laser foaming to obtain a cross section of the polymer material, and observing and calculating the average cell diameter of a foaming area by using a scanning electron microscope.

TABLE 1 laser foaming Effect

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The results in the table 1 show that the laser foaming auxiliary agent prepared by the method of the invention by using graphene oxide, boron nitride, a coupling agent and a thermoplastic polymer is applied to various colored polymer materials such as polypropylene (PP), epoxy resin, cycloolefin copolymer (COC), acrylonitrile-butadiene-styrene copolymer (ABS), high-density polyethylene (HDPE), ethylene-octene copolymer (POE) and the like, the foaming height can reach more than 1.88mm, and compared with the prior art, the result has very remarkable laser foaming effect.

More importantly, the results of examples 1-3 show that for thermosetting resins (epoxy resins), the very good laser foaming effect can be realized, the defect of poor laser foaming effect of the thermosetting resins is overcome, the application field of the laser foaming technology is widened, and the application requirements of the industry on various polymer materials are met.

Further, it was found by comparison with comparative examples 1 to 14 that a very good foaming effect was obtained only by selecting graphene oxide having a specific oxygen content, number of sheets and sheet diameter in the present invention and combining it with boron nitride, a coupling agent and a thermoplastic polymer having a specific number of sheets and sheet diameter in a specific ratio.

In summary, the invention provides a novel and efficient laser foaming auxiliary composition, which limits the weight ratio of graphene oxide, boron nitride, coupling agent and thermoplastic polymer. The laser foaming can be rapidly realized on various polymer materials with different colors through laser irradiation, meanwhile, the same foaming effect is realized on thermoplastic polymer and thermosetting polymer materials, the foam cell structure of a foaming area is very uniform, and the technical problem in the field is solved. The invention not only widens the application field of laser foaming, but also provides a new technical approach for preparing the color polymer material capable of being foamed by laser, has very good economic benefit and is easy for industrial application.

Claims

1. The laser foaming auxiliary agent composition is characterized by comprising boron nitride, graphene oxide, a coupling agent and a thermoplastic polymer;

the mass ratio of the boron nitride to the graphene oxide to the coupling agent to the thermoplastic polymer is 1: (1-15): (0.05-0.3): (1-30);

the boron nitride is nano particles with lamellar structure, and the average lamellar diameter in the boron nitride particles is below 90 mu m; the graphene oxide is a nano particle with a lamellar structure, and the average lamellar diameter in the graphene oxide particle is less than 90 mu m;

The oxygen content of the graphene oxide is 25-55wt%.

2. The laser foaming auxiliary composition according to claim 1, wherein the mass ratio of the boron nitride to the graphene oxide to the coupling agent to the thermoplastic polymer is 1: (1-10): (0.05-0.2): (1-15).

3. The laser foaming aid composition according to claim 1, wherein the average platelet diameter in the boron nitride particles is 60 μm or less.

4. A laser foaming aid composition according to claim 3, characterized in that the average platelet diameter in the boron nitride particles is 9-15 μm.

5. The laser foaming aid composition according to claim 1, wherein the number of the lamellar layers of the boron nitride particles is 200 or less.

6. The laser foaming aid composition according to claim 5, wherein the number of the lamellar layers of the boron nitride particles is 125 or less.

7. The laser foaming aid composition according to claim 6, wherein the number of the lamellar layers of the boron nitride particles is 13 to 90.

8. The laser foaming aid composition according to claim 1, wherein the average platelet diameter in the graphene oxide particles is 60 μm or less.

9. The laser foaming aid composition according to claim 8, wherein the average platelet diameter in the graphene oxide particles is 8 to 16 μm.

10. The laser foaming aid composition of claim 8, wherein the graphene oxide has an oxygen content of 35 to 55wt%.

11. The laser foaming aid composition according to claim 1, wherein the number of lamellar layers of the graphene oxide particles is 80 or less.

12. The laser foaming aid composition according to claim 11, wherein the number of lamellar layers of the graphene oxide particles is 50 or less.

13. The laser foaming aid composition of claim 12, wherein the number of lamellar layers of the graphene oxide particles is 5-39.

14. The laser foaming auxiliary composition according to claim 1, wherein the coupling agent is selected from any one or more of silane coupling agent, titanate coupling agent, zirconate coupling agent and phosphate coupling agent.

15. The laser foaming aid composition according to claim 14, wherein the coupling agent is selected from any one or more of silane coupling agents a-151, KH-550, KH-560, KH-570, KH-580, Z-6030.

16. The laser foaming aid composition according to claim 1, wherein the thermoplastic polymer is selected from polymer materials containing aromatic or alicyclic structures.

17. The laser foaming aid composition according to claim 16, wherein the thermoplastic polymer is selected from any one or more of polyethylene terephthalate, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene copolymer, styrene-acrylonitrile copolymer, polybutylene terephthalate, aromatic polyamide, polyphenylene oxide, polyimide, polysulfone, polyetheretherketone.

18. A method of preparing the laser foaming aid composition of any of claims 1-17, comprising the steps of:

19. The method according to claim 18, wherein in step 1), the concentration of the thermoplastic polymer dissolved in the organic solvent is 1 g/(1 to 500) mL;

in the step 2), the dispersion concentration of the graphene oxide and the boron nitride in the alcohol solvent is 1 g/(10-1000) mL based on the total mass of the graphene oxide and the boron nitride;

in the step 3), the concentration of the coupling agent added into the water/alcohol mixed solution is 1 g/(160-1000 mL).

20. The process according to claim 19, wherein in step 1), the concentration of the thermoplastic polymer dissolved in the organic solvent is 1 g/(10 to 200) mL.

21. The production method according to claim 19, wherein in step 2), the concentration of the graphene oxide and the boron nitride dispersed in the alcoholic solvent is 1 g/(10 to 100) mL, based on the total mass of both.

22. The method according to claim 19, wherein in step 3), the coupling agent is added to the water/alcohol mixed solution at a concentration of 1 g/(260 to 842 mL).

23. The method according to claim 18, wherein in step 1), the organic solvent is any one or more of benzene, toluene, xylene, chlorobenzene, dichloromethane, chloroform, N-dimethylformamide, dimethyl sulfoxide, acetone, tetrahydrofuran, cyclohexane, and N-hexane.

24. The method according to claim 18, wherein in step 2), the alcohol solvent is any one or more of ethanol, methanol, propanol, and isopropanol.

25. The method according to claim 18, wherein in step 2), the ultrasonic treatment is performed at an ultrasonic power of 100 to 1500W for 5 to 18 hours.

26. The method of claim 25, wherein the ultrasonic power is 500-1300W and the ultrasonic treatment time is 5-15 h.

27. The method according to claim 18, wherein in step 3), the volume ratio of water to alcohol in the mixed solution of water and alcohol is 0.5-2: 50.

28. the method according to claim 18, wherein in step 3), the alcohol is any one or more of ethanol, methanol, propanol, and isopropanol.

29. The method according to claim 18, wherein in step 3), the pre-hydrolysis is performed at a temperature of 25 to 100 ℃ for a time of 0.5 to 3 hours.

30. The process of claim 29, wherein the pre-hydrolysis is carried out at a temperature of 25 to 60 ℃ for a time of 1.5 to 3 hours.

31. Use of the laser foaming aid composition of any of claims 1-17 or the laser foaming aid composition prepared by the method of any of claims 18-30 for the preparation of a laser foamed material.

32. A laser foaming polymer material, which is characterized by comprising a colored polymer base material and a laser foaming auxiliary agent composition;

the laser foaming aid composition is the laser foaming aid composition of any one of claims 1-17 or the laser foaming aid composition prepared by the method of any one of claims 18-30.

33. The laser foamed polymeric material of claim 32, wherein the laser foaming aid composition is 5-45% of the mass of the colored polymeric substrate material.

34. The laser foamed polymeric material of claim 33, wherein the laser foaming aid composition is 25-45% of the mass of the colored polymeric substrate material.

35. The laser foamed polymeric material of claim 32, wherein the colored polymeric substrate material comprises a thermoplastic polymeric material and a thermoset polymeric material; the thermoplastic polymer material is selected from any one or more of low-density polyethylene, high-density polyethylene, polypropylene, cycloolefin copolymer, ethylene-octene copolymer, ethylene-butene copolymer, polycarbonate, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer, thermoplastic polyurethane elastomer, polystyrene, styrene-butadiene-styrene block copolymer, polyamide, polyoxymethylene, polyethylene terephthalate, polybutylene terephthalate, polylactic acid and poly adipic acid/butylene terephthalate; the thermosetting polymer material is selected from any one or more of epoxy resin, phenolic resin, urea resin, unsaturated polyester and melamine-formaldehyde resin.

36. A method of preparing a laser foamed polymeric material according to any one of claims 32 to 35, comprising the steps of:

37. The method of preparing as claimed in claim 36, wherein the steps comprise: the conditions of the laser induced foaming are as follows:

the laser wavelength is 193 nm-10.6 mu m; the laser scanning speed is 100-2000 mm/s; the laser energy is 5-30W.

38. The method of preparing as claimed in claim 37, wherein the steps comprise: the laser scanning speed is 1000-2000 mm/s.

39. The method of preparing as claimed in claim 37, wherein the steps comprise: the laser energy is 8-20W.