CN104559196B - Colorless and transparent light-cured 3D printing material - Google Patents

Abstract

A colorless and transparent light-cured 3D printing material belongs to the technical field of curing materials. The printing material includes organopolysiloxane containing vinyl group, organopolysiloxane containing silicon-hydrogen bond, photoinitiator, reinforcing filler and auxiliary agent. The preparation method of the material is as follows: mix and stir vinyl-containing organopolysiloxane, silicon-hydrogen bond-containing organopolysiloxane, reinforcing fillers and additives according to mass percentage; then add photoinitiator, stir and mix evenly , to obtain a colorless photocurable 3D printing material. The beneficial effects of the present invention are: (1) the photocured product is colorless, has good transparency and elasticity; (2) the molding shrinkage rate of the material after photocuring is low, and the volume shrinkage rate is lower than 1.0%; (3) all The components are all involved in curing, no volatile solvents, and no pollution; (4) Wide applicability to curing light sources, the longest wavelength of curable light is 405nm.

Description

A colorless and transparent photocurable 3D printing material

technical field

The invention belongs to the field of curing materials, in particular to a colorless and transparent light-curing 3D printing material and a preparation method thereof.

Background technique

Organosilicon polymers are semi-inorganic and semi-organic polymer compounds with silicon-oxygen bonds as the main chain and side chains through silicon and organic groups. The special structure endows it with many excellent properties, such as high and low temperature resistance, weather resistance, aging resistance, corrosion resistance, low surface tension and physiological inertia. Light curing technology has the advantages of fast curing, low energy consumption, high efficiency, and no pollution. It fully complies with the "3E" principle: Energy (energy saving), Ecology (ecology and environmental protection), and Economy (economy). It is an environmentally friendly green technology. Light-curing silicone materials are favored due to the excellent performance of silicone materials and the high-efficiency and energy-saving features of light-curing technology, and are gradually being widely used. The combination of silicone materials and light-curing technology not only expands the application of silicone materials to new fields, but also adds new and excellent types of light-curing materials.

Generally speaking, the photocurable silicone system is mainly composed of three components: photosensitive polysiloxane (organic silicon prepolymer), photoinitiator and reactive diluent. In addition, according to the specific application, other fillers or additives can also be added.

Photocurable silicone is mainly divided into 6 types according to its reaction type: mercapto-vinyl addition reaction type, free radical curing reaction type, cationic curing reaction type, styryl polysiloxane, vinyl ether functional polysilicon Oxane and hydrosilylation forms.

(1) Mercapto-vinyl addition reaction type silicone system vinyl-containing linear polymethylvinylsiloxane, and mercapto-containing polymethylsiloxane, in the presence of a photosensitizer, irradiated by ultraviolet light And solidified. The photoresponse speed of the system is fast, and it is not interfered by oxygen inhibition, and can form a soft and elastic cured film. However, the storage stability of this system is not ideal. The longer the time, the viscosity of the system will gradually increase, and the tensile strength of the cured film will tend to decrease; in addition, the mercaptan in the system has a strong odor, and the silicone polysulfide Alcohols are more expensive than traditional hydrocarbon-based polythiols, which is difficult for the market to accept.

(2) Free radical curing reactive silicone is mainly acrylated polysiloxane, which has won the market due to its high reactivity and low cost, and has become a hot spot in the research field of photosensitive silicone prepolymers. Acrylate groups can react by free radical reaction mechanism under ultraviolet light irradiation. The photocuring reactivity of the acrylate group is generally high, the reaction rate is fast, the chemical and physical stability of the cured layer is good, the ideal viscosity can be obtained by adjusting the formula, and it has a certain ability to resist oxygen polymerization, and the price is low. In 1979, the French Rhone-Poulenc company developed a UV-curable silicone acrylate. In 1983, Goldschmidt first introduced free radical light-cured silicone acrylate to the market as a release coating (also known as release agent, anti-sticking agent). However, the system is usually accompanied by volume shrinkage during the curing process, and the oxygen inhibition effect is obvious, so that it needs nitrogen protection during photocuring.

(3) Cationic curing reactive silicone system. Linear polyorganosiloxane containing epoxy groups is cured by ultraviolet light irradiation in the presence of cationic photoinitiators. When the epoxy group undergoes cationic photopolymerization, the epoxy group with ring tension is opened to form a tension-free ether bond, and the volume shrinkage is very small or even zero; therefore, epoxy-functional polysiloxane photopolymerization It does not shrink like acrylated polysiloxane, which is a big advantage. GE has done a lot of work on the synthesis and performance of epoxy-functionalized polysiloxanes, and the commercialized epoxy-functionalized polysiloxanes mainly come from this company. Unsaturated epoxy compounds commonly used to modify organosiloxanes are mainly epoxy-based compounds containing vinyl or allyl groups, such as allyl glycidyl ether, glycidyl acrylate, dicyclohexene pentadiene and 4-vinyl-1,2-epoxycyclohexene, etc. During the hydrosilylation reaction, the presence of a platinum catalyst tends to lead to the formation of heterocyclic epoxidized polysiloxane, and also to the ring-opening reaction of epoxy groups, which will lead to the generation of gel and also make the ring The shelf life of oxylated polysiloxane is significantly reduced, so it is necessary to add a tertiary amine stabilizer to the reaction system.

(4) Vinyl ether monomers are monomers containing H ₂ C=CH-O-groups. The carbon-carbon double bond of vinyl ether is an electron-rich double bond, its reactivity is higher than that of general vinyl monomers, and it can undergo free radical polymerization, cationic polymerization and alternate copolymerization of charge transfer complexes. Therefore, vinyl ether polysiloxane can be applied in various photocuring systems, such as free radical system, cationic system and hybrid system (free radical curing and cationic curing exist at the same time). Vinyl ether resin has gradually attracted people's attention due to its high reactivity, low toxicity, low odor, and high viscosity. However, the price of synthetic raw material vinyl ether is relatively high, making vinyl ether light-curing materials popular in the domestic light-curing industry. It has not yet achieved general application.

(5) Styrene base is also photosensitive, and cheap styrene and its derivatives have good copolymerization properties with many resins, which can improve the hardness and mechanical strength of the cured film. If styrene groups are introduced into polysiloxane molecules, it can not only endow polysiloxane with photosensitivity, but also overcome the disadvantage of low strength of pure silicone resin. The biggest advantage of styrene-based polysiloxane UV curing system is its low price. The photocuring system also has many disadvantages, such as high volatility, high flammability, strong odor, slow reaction speed, etc., and the curing performance is not as good as other photocuring systems.

(6) The curing mechanism of the hydrosilylation reaction silicone system is that vinyl-containing polymethylvinylsiloxane and linear polyhydrogenmethylsiloxane are cured by ultraviolet light under the action of a platinum catalyst. The system does not require photosensitizing modification of the organosiloxane, and the photocuring reaction can be carried out by using the existing organosilicon resin in the presence of a photoinitiator, which simplifies the reaction process and reduces the cost. However, the current research mainly focuses on the UV curing system, and there is less research on the visible light-sensitive silicone curing system.

Contents of the invention

The main purpose of the present invention is to provide a colorless and transparent 3D printing material using a metal complex photoinitiator;

Another object of the present invention is to provide a method for preparing a colorless, transparent and elastic 3D printing material.

To achieve the above object, the present invention adopts the following technical solutions:

A colorless and transparent light-curing 3D printing material, its formula is as follows:

Further, the organopolysiloxane containing vinyl groups contains at least two vinyl groups linked to silane in each molecule, the vinyl content is 0.1-10.0wt%, the viscosity is 100-10000mPa·S, ethylene The vinyl group in the base silicone oil is located at the end of the molecular chain or in the middle of the molecular chain, including compounds of the following formulas I, II and III:

Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are the same or different hydrocarbon groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and It can be vinyl, phenyl, 3,3,3-trifluoropropyl; different R3 or R4 can make formula I a copolymer; n is an integer.

Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different hydrocarbon groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl The group can also be vinyl, phenyl, 3,3,3-trifluoropropyl; Vi is vinyl; n is an integer ≥ 2, and m is also an integer.

Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different hydrocarbon groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl The group can also be a vinyl group or a phenyl group; Vi is a vinyl group; n is an integer ≥ 2, and m is also an integer.

Further, the vinyl group-containing organopolysiloxane includes dimethylvinylsiloxy-terminated dimethylpolysiloxane, dimethylvinylsiloxy-terminated dimethylsiloxane Copolymer with methyl phenyl siloxane, dimethyl vinyl siloxy-terminated copolymer of dimethyl siloxane and methyl vinyl siloxane, dimethyl vinyl siloxy-terminated dimethicone Copolymer of methylsiloxane and diphenylsiloxane, dimethylvinylsiloxy-terminated copolymer of dimethylsiloxane, diphenylsiloxane and methylvinylsiloxane , Copolymers of dimethylvinylsiloxy-terminated dimethylsiloxane, methylphenylsiloxane and methylvinylsiloxane, dimethylhydroxyl-terminated vinylpolysiloxane, Copolymer of dimethyl hydroxysiloxy-terminated dimethyl siloxane and methyl vinyl siloxane, dimethyl hydroxy-terminated dimethyl polysiloxane and methyl phenyl siloxane and methyl Copolymer of vinyl vinyl siloxane, copolymer of dimethyl hydroxysiloxy terminated dimethyl siloxane with diphenyl siloxane and methyl vinyl siloxane, trimethyl siloxy End-blocked vinyl polysiloxane, copolymer of trimethylsiloxy-terminated dimethylsiloxane and methylvinylsiloxane, trimethylsiloxy-terminated dimethylsiloxane and Copolymers of methylbenzene and siloxane and methylvinylsiloxane, trimethylsiloxy-terminated dimethylsiloxane and diphenylsiloxane and diphenylsiloxane and methyl Copolymer of vinyl siloxane.

Further, each molecule of the organopolysiloxane containing silicon-hydrogen bonds contains at least three hydrogen atoms connected to silicon, and the hydrogen content is 0.3-3.0 wt%. Including trimethylsiloxy-terminated methylhydrogen polysiloxane, copolymer of trimethylsiloxy-terminated dimethylsiloxane and methylhydrogensiloxane, dimethylhydrogensiloxy-terminated Terminated methylhydrogenpolysiloxane, copolymer of dimethylhydrogensiloxy-terminated dimethylsiloxane and methylhydrogensiloxane, composed of (CH3) ₃ SiO _1/2 segment, ( CH3) ₂ HSiO _1/2 segment and SiO ₂ segment composed of copolymers.

Further, the photoinitiator is a platinum-based catalyst for the addition reaction of polysiloxane containing silicon hydrogen atoms and polysiloxane containing silicon hydrogen groups, and the platinum-based catalyst includes chloroplatinic acid, Alcohol or ketone solution of chloroplatinic acid, complexes of chloroplatinic acid and olefin, complexes of chloroplatinic acid and vinylsiloxane, complexes of chloroplatinic acid and diethyl phthalate.

Further, the reinforcing filler includes one or a mixture of fumed silica, precipitated silica, vinyl-containing MQ resin, MT resin, MD resin, MTQ resin, MDQ resin, and MDT resin , The viscosity of the reinforced filler is 1000--30000mPa·s.

Further, the auxiliary agents include defoamers, leveling agents, stabilizers, and inhibitors.

A preparation method of a colorless and transparent light-cured 3D printing material, the specific steps of which are:

(1) Mix and stir vinyl-containing organopolysiloxane, silicon-hydrogen bond-containing organopolysiloxane, reinforcing fillers and additives evenly by mass percentage;

(2) Add a photoinitiator, stir and mix evenly to obtain a colorless light-curable 3D printing material.

Compared with the preparation process of colorless and transparent photocurable 3D printing materials in the prior art, the characteristics of the preparation process of the present invention are: (1) the colorless and transparent 3D printing material uses a metal complex photoinitiator to initiate the hydrosilylation reaction, The curing reaction speed is fast, and the wavelength range of the curable light source is large; (2) The molding shrinkage rate is low, and the cured product is colorless, transparent, and elastic; (3) There is no volatile solvent, the photosensitive resin composition is all involved in curing, and there is no VOC emission. No pollution.

Compared with the prior art, the beneficial effects of the light-cured 3D printing material of the present invention are: the light-cured product is colorless, has good transparency and elasticity; the molding shrinkage of the material after light-curing is low, and the volume shrinkage is lower than 1.0%; the resin All components in the mixture participate in curing, without volatile solvents and pollution; it has wide applicability to curing light sources, and the longest wavelength of curable light is 405nm.

In order to improve the application performance of the light-cured silicone system, the present invention uses a metal complex photoinitiator to initiate the hydrosilicon addition reaction, and improves the formula of the 3D printing material to improve the stability of the light-cured silicone system as much as possible. Improve the curing speed and molding efficiency of 3D printing materials.

The colorless and transparent light-curable 3D printing material in the present invention has a wide range of curable light source wavelengths and fast curing reaction speed, which greatly improves the stability and application range of the light-curable silicone system.

In addition, "part" and "%" in this invention refer to a basis of weight, respectively, unless otherwise specified.

detailed description

Example 1

Preparation Process:

(1) Mix 70g of dimethylvinylsiloxy-terminated dimethylpolysiloxane, 12g of trimethylsiloxy-terminated methylhydrogenpolysiloxane, 7g of fumed silica, and 8g of inhibitor Mix and stir well.

(2) Add 3 g of alcohol solution of chloroplatinic acid to the mixture obtained in (1), stir and mix evenly to obtain a colorless and transparent photocurable 3D printing material.

The light-curing 3D printing material was applied to a light-curing 3D printer in the container, and the printing test was performed at 25°C. The curing rate was fast, and the molded parts had general transparency and high strength.

Example 2

Dimethylvinylsiloxy-terminated copolymer of dimethylsiloxane and methylphenylsiloxane

Preparation Process:

(1) Mix 65g of dimethylvinylsiloxy-terminated dimethylsiloxane and methylphenylsiloxane copolymer, 20g of trimethylsiloxy-terminated dimethylsiloxane and methyl The copolymer of hydrogen siloxane, 10g of vinyl-containing MQ resin, and 4g of defoamer were mixed and stirred evenly.

(2) Add 1 g of the complex of chloroplatinic acid and diethyl phthalate to the mixture obtained in (1), stir and mix evenly to obtain a colorless and transparent photocurable 3D printing material.

The light-curing 3D printing material was applied to a light-curing 3D printer in the container, and the printing test was performed at 25°C. The curing rate was fast, and the molded parts had good transparency and high strength.

Example 3

Preparation Process:

(1) Mix 40g of dimethylvinylsiloxy-terminated dimethylpolysiloxane, 30g of trimethylsiloxy-terminated methylhydrogenpolysiloxane, 20g of fumed silica, and 9.999g of inhibitor The agent is mixed and stirred evenly.

(2) Add 0.001 g of an alcohol solution of chloroplatinic acid to the mixture obtained in (1), stir and mix evenly to obtain a colorless and transparent photocurable 3D printing material.

The light-curing 3D printing material was applied to a light-curing 3D printer in a container, and the printing test was performed at 25°C. The curing rate was slow, and the molded parts had general transparency and low strength.

Example 4

Preparation Process:

(1) Mix 74.9g of dimethyl vinylsiloxy-terminated dimethylsiloxane and methylphenylsiloxane copolymer, 5g of trimethylsiloxy-terminated dimethylsiloxane and methyl Mix and stir the copolymer of polyhydrogen siloxane, 0.1 g of vinyl-containing MQ resin, and 10 g of defoamer evenly.

(2) Add 10 g of the complex of chloroplatinic acid and diethyl phthalate to the mixture obtained in (1), stir and mix evenly to obtain a colorless and transparent photocurable 3D printing material.

The light-curing 3D printing material was applied to a light-curing 3D printer in a container, and the printing test was performed at 25°C. The curing rate was fast, and the molded parts had good transparency and general strength.

Example 5

Preparation Process:

(1) 90g dimethyl vinylsiloxy-terminated dimethylpolysiloxane, 5g trimethylsiloxy-terminated methylhydrogenpolysiloxane, 1.5g fumed silica, 0.5g Inhibitor mix and stir well.

(2) Add 3 g of alcohol solution of chloroplatinic acid to the mixture obtained in (1), stir and mix evenly to obtain a colorless and transparent photocurable 3D printing material.

The light-curing 3D printing material was applied to a light-curing 3D printer in the container, and the printing test was performed at 25°C. The curing rate was fast, and the molded parts had general transparency and strength.

Claims (6)

1. a kind of water white photocuring 3D printing material, it is characterised in that：Component comprising following mass percent：

The light trigger is platinum group catalyst, and the platinum group catalyst includes chloroplatinic acid, the alcohol of chloroplatinic acid or ketone solution, chlorine platinum Acid and the coordination compound of diethyl phthalate；

The each intramolecular of the organopolysiloxane containing vinyl group is at least containing two vinyl groups being connected with silane, second Amount vinyl content is 0.1-10.0wt%, and viscosity is 100-10000mPaS, and the vinyl in vinyl silicone oil is located at molecule last-in-chain(LIC) Hold or in the middle of strand, including the one kind in the compound of lower formula I, II and III：

Wherein R¹、R²、R³、R⁴、R⁵、R⁶For identical or different alkyl, n is integer；

Wherein R¹、R²、R³、R⁴、R⁵、R⁶And R⁷For identical or different alkyl, Vi is vinyl, and n is >=2 integer, and m is also for whole Number；

Wherein R¹、R²、R³、R⁴、R⁵、R⁶And R⁷For identical or different alkyl, Vi is vinyl；N is >=2 integer, m is also for whole Number.

2. a kind of water white photocuring 3D printing material as claimed in claim 1, it is characterised in that：It is described containing vinyl The organopolysiloxane of group includes dimethyl polysiloxane, the dimethyl ethenyl siloxy of dimethyl ethenyl siloxy end-blocking The dimethyl siloxane that the dimethyl siloxane of end-blocking is blocked with methyl phenyl siloxane copolymer, dimethyl ethenyl siloxy The dimethyl siloxane and diphenyl siloxane of copolymer, the dimethyl ethenyl siloxy end-blocking with methyl vinyl silicone Copolymer, dimethyl ethenyl siloxy end-blocking dimethyl siloxane and diphenyl siloxane and methyl vinyl silicone Copolymer, dimethyl ethenyl siloxy end-blocking dimethyl siloxane and methyl phenyl siloxane and methyl ethylene silica The copolymer of alkane, the vinyl polysiloxane of dimethyl hydroxyl end-blocking, the dimethyl siloxane of dimethyl hydroxyl siloxy end-blocking The dimethyl polysiloxane and methyl phenyl siloxane and first of copolymer, the dimethyl hydroxyl end-blocking with methyl vinyl silicone Dimethyl siloxane and diphenyl siloxane and methyl that the copolymer of base vinylsiloxane, dimethyl hydroxyl siloxy are blocked The copolymer of vinylsiloxane, the vinyl polysiloxane of trimethylsiloxy group end-blocking, the diformazan of trimethylsiloxy group end-blocking Dimethyl siloxane and methylbenzene and silicon that the copolymer of radical siloxane and methyl vinyl silicone, trimethylsiloxy group are blocked The copolymer of oxygen alkane and methyl vinyl silicone, the dimethyl siloxane of trimethylsiloxy group end-blocking and diphenyl siloxane and At least one in the copolymer of diphenyl siloxane and methyl vinyl silicone.

3. a kind of water white photocuring 3D printing material as claimed in claim 1, it is characterised in that：The silicon-hydrogen bond containing The each intramolecular of organopolysiloxane at least containing three hydrogen atoms being connected with silicon, hydrogen content is 0.3-3.0wt%, including Dimethyl siloxane and methyl hydrogen siloxane that the methylhydrogenpolysi,oxane of trimethylsiloxy group end-blocking, trimethylsiloxy group are blocked Copolymer, dimethyl hydrogen siloxy block your methylhydrogenpolysi,oxane, dimethyl hydrogen siloxy end-blocking dimethyl silica The copolymer of alkane and methyl hydrogen siloxane, by (CH₃)₃SiO_1/2Segment, (CH₃)₂HSiO_1/2Segment and SiO₂The copolymerization of segment composition At least one in thing.

4. a kind of water white photocuring 3D printing material as claimed in claim 1, it is characterised in that：The reinforcer Including fumed silica, precipitated silica, the MQ resins containing vinyl, MT resins, MD resins, MTQ resins, MDQ The mixture of one or more in resin, MDT resins, reinforcer viscosity is 1000--30000mPas.

5. a kind of water white photocuring 3D printing material as claimed in claim 1, it is characterised in that：The auxiliary agent includes At least one in defoamer, levelling agent, stabilizer, inhibitor.

6. a kind of preparation method of water white photocuring 3D printing material as claimed in claim 1, it is characterised in that：Bag Include following steps：(1) by the organopolysiloxane containing vinyl, the organopolysiloxane of silicon-hydrogen bond containing, reinforcer and auxiliary agent Mixing and stirring by mass percentage；(2) light trigger is added, is uniformly mixed, obtain colourless photocuring 3D printing Material.