CN1322059C - Technology for continuously making single-component mist-solidifying silicon-ketone composition - Google Patents

Abstract

The present invention discloses a technology for continuously making single-component mist-solidifying silicon-ketone compositions. In the technology, components forming single-component mist-solidifying silicon-ketone compositions are added to a continuous production line to react to produce the single-component mist-solidifying silicon-ketone compositions. The components of the single-component mist-solidifying silicon-ketone compositions comprise polysiloxane, filling materials, plasticizing agents, crosslinking agents, coupling agents and catalysts; the continuous production line comprises a group of double-screw extruder groups connected in series, a metering device, a cooler and a dispensing device. The present invention has the advantages of high production efficiency, low labor intensity, large production capacity, suitable scale production, little loss of materials and energy sources and cost saving; products have the advantages of high uniform quality and high stability.

Description

A continuous manufacturing process of a one-component moisture-curing silicone composition

technical field

The invention relates to a manufacturing process of a one-component moisture-curing silicone composition.

Background technique

Usually, the one-component moisture-curing silicone composition is packaged in an airtight container and taken out of the container when used. The composition exposed to the air reacts with water in the air at room temperature and solidifies into an elastomer, which is usually used as Sealants and adhesives. Because of its single-package, solvent-free, and room-temperature curing, it is extremely convenient to use and has superior performance. It is widely used in industries such as construction, electronics, and machine manufacturing. The components of a one-component moisture-curing silicone composition generally include: (1) polysiloxane; (2) fillers, such as calcium carbonate, white carbon black, etc.; (3) plasticizers, such as simethicone , mineral oil, etc.; (4) catalysts, such as organotin, organotitanium, etc.; (5) crosslinking agents, such as methyltrimethoxysilane, methyltributanoximinosilane, etc.; (6) coupling agents, Such as γ-aminopropyltriethoxysilane, epoxypropyltrimethoxysilane and so on.

The manufacturing process of one-component moisture-curing silicone composition is commonly used as follows:

(1) Planetary mixer method. The basic process of this process is to initially mix polysiloxane, fillers and additives with mixing equipment such as a kneader, so that the polymer and filler are mixed uniformly and fully dispersed, and low boiling substances and moisture are removed. Grinding with a roller machine, then moving into a planetary mixer for further mixing, adding pigments, crosslinking agents, coupling agents and catalysts, etc., and vacuum foaming to obtain the product. Most manufacturers use this method to produce. The advantage of this process is that the production process is simple and easy to operate, the formula and process can be adjusted at any time, and the product variety and color can be replaced; the disadvantage is that the material is exposed to the air during transfer, and skinning is easy to occur when producing in hot and humid weather or producing fast-curing products ; Large loss during material transfer; production stability is poor, the quality of each batch is different; slow and time-consuming.

(2) Static mixer method. The basic process of this process is to first mix the dried polysiloxane, fillers and additives with mixing equipment such as a kneader, and then mix them with colorants, crosslinking agents and catalysts through a static mixer to obtain the product. The advantage of this process is that the production process is simple, the color can be easily changed, the material loss is small, and the labor intensity is relatively light; the disadvantage is that the process is poorly adjustable, the by-products in the production process cannot be removed, and the variety of sealants produced is limited.

(3) Twin-screw extruder method. At present, the process of using a twin-screw extruder to manufacture a one-component moisture-curing silicone composition is a twin-screw extruder. The filler is dispersed in advance, and then various materials are added to the twin-screw extruder for mixing and reaction. Made products. This process has the following disadvantages: First, the premixing of fillers is very difficult, usually in a kneader or high-speed disperser, and in most cases it needs to be ground by a three-roller machine, which is labor-intensive, quality fluctuates, and output is low; Secondly, the viscosity of the paste formed after the pre-dispersion of the filler is extremely high, and it is very difficult to add quantitatively and accurately to the twin-screw extruder, which requires very complicated equipment and technology to achieve; it takes a long time to complete the production with a twin-screw extruder. High-quality twin-screw, the ratio of length to diameter needs to be large, and the requirements for equipment are high.

Contents of the invention

The object of the present invention is to overcome the deficiency of above-mentioned single twin-screw extruder technology and provide a kind of continuous manufacturing process of new one-component moisture curing silicone composition, this process does not need premixing or pretreatment, and process The parameters are more adjustable, and the production operation is more flexible.

The invention provides a continuous manufacturing process for a one-component moisture-curing silicone composition, which is to add the components that make up the one-component moisture-curing silicone composition into a continuous production line for reaction to produce One-component moisture-curing silicone composition, the components of the one-component moisture-curing silicone composition include polysiloxane, filler, plasticizer, crosslinking agent, coupling agent and catalyst, the The continuous production line includes a set of serial twin-screw extruders, metering devices, coolers and packaging equipment. The serial twin-screw extruders are two or more twin-screw extruders. The machine is equipped with a material inlet, a material outlet and a vacuum port. The twin-screw extruders are connected together through a cooler. The front one is called the first-stage machine, the back one is called the second-stage machine, and so on; At the end of the continuous production line.

In the continuous production line of the present invention, a buffer tank is also connected between the serial twin-screw extruder unit and the packaging equipment, and a filter is arranged at the outlet of the twin-screw extruder, and the twin-screw extruder adopts Co-rotating twin-screw extruder.

In the continuous manufacturing process of the present invention, polysiloxane and filler are added in the first-stage machine through a metering device, and when polysiloxane is added to the first-stage machine, it is added at least at two separate feed ports; crosslinking agent, The coupling agent and catalyst are added in the second-stage machine, and can be added separately or mixed; the plasticizer is added in the first-stage machine or the second-stage machine.

The components of the one-component moisture-curing silicone composition described in the present invention are respectively:

Polysiloxane is R"O-[SiORR']n-SiOR", wherein: n=10~10000, R is methyl, ethyl, vinyl or phenyl, R' is methyl, ethyl, vinyl base or phenyl, R" is H, methyl, ethyl or propyl;

The filler can be calcium carbonate, fumed silica, precipitated silica, barium sulfate, iron oxide, aluminum silicate or quartz powder;

The plasticizer can choose simethicone or mineral oil;

The catalyst can be an organic tin catalyst or an organic titanium catalyst, wherein the organic tin catalyst is dibutyltin dilaurate, dibutyltin diacetate or stannous octoate; the organic titanium catalyst is (R ₁ )Ti(R ₂ ) ₂ or (R ₃ ) ₂ Ti(R ₂ ) ₂ , wherein R ₁ is 1,3 propylene glycol, 1,2 propylene glycol or butanediol, R ₂ is acetylacetone or ethyl acetoacetate, R ₃ is ethanol, propanol, isopropanol or butane alcohol;

The crosslinking agent is (R ₄ )nSi(R ₅ )m, where m+n=4, m=3 or 4, n=0 or 1, R ₄ is methyl, ethyl, vinyl or phenyl, R ₅ is methoxy, ethoxy, propoxy, isopropoxy, butoxy, acetoxy, acetone oxime, butanone oxime or propyleneoxy;

The coupling agent is (R ₆ )Si(R ₇ ) ₃ , wherein R ₆ is amino, chloropropyl, vinyl, phenyl, mercapto, alkoxy or epoxyalkyl, and R ₇ is methoxy or Ethoxy.

Compared with the manufacturing process of the existing one-component moisture-curing silicone composition, the present invention has the following characteristics:

(1) The present invention is a continuous production method, the production capacity is much higher than the batch production method, and the labor intensity is greatly reduced;

(2) There is no intermediate product in the manufacturing process of the present invention, and there is no intermediate product inventory;

(3) The present invention is a continuous production method, without cleaning equipment in the middle, without material waste, and with high yield;

(4) The whole production process of the present invention is an airtight process, no material is exposed to the air, does not pollute the environment, and does not endanger the health of the operator;

(5) Compared with the single-stage twin-screw extruder production technology, the process parameters of the present invention have greater adjustability, the production operation is flexible, and no premixed materials are needed in the manufacturing process;

(6) Two twin-screw extruders of the present invention can be debugged step by step, and the material just enters the second-stage machine after the first-stage machine is debugged, and the material debugged by the first-stage machine can also be recycled like this, while the single-stage twin-screw extruder The machine production technology cannot be achieved, and the materials produced during the debugging process cannot be used;

(7) The present invention installs a cooler between the serial twin-screw extruders, which can accurately control the temperature of the material entering the second-stage machine, which is beneficial to the material reaction in the second-stage machine;

(8) The present invention installs a buffer tank before entering the packaging machine, so that the continuous production of the whole process becomes possible, and it is not necessary to pack the product into a vat and then subpackage, thereby avoiding the particles, crusts and air bubbles generated when the product is subcontracted in a large package .

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Detailed ways

What Fig. 1 showed is the production process flowchart of the present invention. A part (accounting for 20-80% of the total amount of polysiloxane) of polysiloxane and filler is quantitatively input into the first-stage machine from the feed port 1 and 2 through the metering device, and the 3rd stage of the first-stage machine is a strong kneading section. Polysiloxane and filler are mixed here to form a high-viscosity paste. Under the action of the high-strength mixing unit, the filler is fully dispersed in the polysiloxane. 4 is the vacuum port to absorb the moisture in the mixture. And low boiling matter removal. The material enters 5 after passing through the kneading section 3, and the 5th is a strong kneading section, where the high-viscosity material is further dispersed, and another part (accounting for 80-20% of the total amount of polysiloxane) polysiloxane is in the feed port 6 is added, and 7 is a vacuum port to further remove moisture and low boilers in the mixture. 8 is a filter, and the impurities therein are filtered out when the material passes through. 18 is a discharge port, and the material enters the cooler 9 after coming out of the first-stage machine, and its temperature drops from above 100°C to below 50°C. The material cooled by the cooler 9 enters the second-stage machine, and the cross-linking agent, catalyst coupling agent, and plasticizer are added through the feed ports 10, 11, and 12. The materials are mixed and reacted in the mixing section 13, and 14 is a vacuum port. to remove by-products of the reaction. The 15th is a filter, and the 19th is a discharge port, and the reaction product goes to the packaging equipment 17 and is subpackaged into products after the buffer tank 16.

Example 1

The components and weight ratio of the one-component moisture-curing silicone composition are:

Hydroxy-terminated polysiloxane 100

Nano active calcium carbonate (40nm) 100

Simethicone (0.1Pa.s) 3

Methyltrimethoxysilane 25

γ-Aminopropyltriethoxysilane 0.5

Ethyl acetoacetate titanium chelate 2

The hydroxyl-terminated polysiloxane is input into the first-stage machine at 500Kg/hr, 250Kg/hr at the 1 feed port, and 250Kg/hr at the 2 feed port, and other materials are added in proportion to the corresponding positions. Control the temperature of the material at the outlet of the first-stage machine to 150°C, the temperature of the material entering the second-stage machine is less than 25°C, the temperature of the material at the outlet of the second-stage machine is 3-5°C, and the vacuum degree of the 4, 7, and 14 vacuum ports is greater than -0.095MPa. The performance of the obtained product:

Surface dry time: 30min

Hardness: 45ShoreA

Tensile strength: 1.56MPa

Elongation: 453%

Example 2

The components and weight ratio of the one-component moisture-curing silicone composition are:

Hydroxy-terminated polysiloxane 100

Nano active calcium carbonate (40nm) 100

Simethicone (0.1Pa.s) 3

Vinyl tributylketoxime silane 5

Methyltributanoximinosilane 30

γ-Aminopropyltriethoxysilane 0.5

Dibutyltin dilaurate 0.3

The hydroxyl-terminated polysiloxane is input into the first-stage machine at 500Kg/hr, 250Kg/hr at the 1 feed port, and 250Kg/hr at the 2 feed port, and other materials are added in proportion to the corresponding positions. Control the temperature of the material at the outlet of the first-stage machine to 150°C, the temperature of the material entering the second-stage machine is less than 50°C, the temperature of the material at the outlet of the second-stage machine is less than 45°C, and the vacuum degree of the 4, 7, and 14 vacuum ports is greater than -0.095MPa. The performance of the obtained product:

Surface dry time: 15min

Hardness: 42ShoreA

Tensile strength: 1.0MPa

Elongation: 270%

Example 3

The components and weight ratio of the one-component moisture-curing silicone composition are:

Hydroxy-terminated polysiloxane 100

Fumed silica (H15, manufactured by Waker Company) 10

Simethicone (0.1Pa.s) 20

Ethyltriacetoxysilane 5

Methyltriacetoxysilane 15

γ-Aminopropyltriethoxysilane 0.5

Dibutyltin dilaurate 0.3

The hydroxyl-terminated polysiloxane is input into the first-stage machine at 500Kg/hr, 250Kg/hr at the 1 feed port, and 250Kg/hr at the 2 feed port, and other materials are added in proportion to the corresponding positions. Control the temperature of the material at the outlet of the first-stage machine to 150°C, the temperature of the material entering the second-stage machine is less than 50°C, the temperature of the material at the outlet of the second-stage machine is less than 45°C, and the vacuum degree of the 4, 7, and 14 vacuum ports is greater than -0.095MPa. The performance of the obtained product:

Surface dry time: 10min

Hardness: 27ShoreA

Tensile strength: 1.10Mpa

Elongation: 250%

Claims (7)

1. A continuous manufacturing process for a one-component moisture-curable silicone composition, characterized in that: the components forming the one-component moisture-curable silicone composition are added to a continuous production line for reaction to produce a single One-component moisture curing silicone composition, the components of the one-component moisture curing silicone composition include polysiloxane, filler, plasticizer, crosslinking agent, coupling agent and catalyst, wherein polysilicon Oxylkane is R``O-[SiORR`]n-SiOR``, wherein: n=10~10000, R is methyl, ethyl, vinyl or phenyl, R` is methyl, ethyl, vinyl group or phenyl, R`` is H, methyl, ethyl or propyl; the cross-linking agent is (R ₄ )nSi(R ₅ ) _m , where m+n=4, m=3 or 4, n= 0 or 1, R ₄ is methyl, ethyl, vinyl or phenyl, R ₅ is methoxy, ethoxy, propoxy, isopropoxy, butoxy, acetoxy, acetone oxime, Butanone oxime or propylene oxide; the continuous production line includes a set of serial twin-screw extruders, metering devices, coolers and packaging equipment, wherein the serial twin-screw extruders are two or more Twin-screw extruder, the twin-screw extruder is equipped with a feed port, a discharge port and a vacuum port. The twin-screw extruders are connected together through a cooler. The front one is called the first-stage machine, and the back one is called the second-stage machine. machine, and so on, the packaging equipment is set at the end of the continuous production line; the polysiloxane and filler are added in the first-stage machine through metering devices; the crosslinking agent, coupling agent, and catalyst are added in the second-stage machine ; After the material comes out of the first-stage machine, it enters the second-stage machine, and its temperature drops from above 100°C to below 50°C. 2. The continuous manufacturing process according to claim 1, characterized in that: when the polysiloxane is fed into the first-stage machine, it is fed into at least two separate feed ports. 3. The continuous manufacturing process according to claim 1, characterized in that: said cross-linking agent, coupling agent, and catalyst are added individually or in combination when added by the second-stage machine. 4. The continuous manufacturing process according to claim 1, characterized in that: said plasticizer is added in a first-stage machine or a second-stage machine. 5. The continuous manufacturing process according to claim 1, characterized in that: said twin-screw extruder is a co-rotating twin-screw extruder. 6. The continuous manufacturing process according to claim 1, characterized in that: a buffer tank is connected between the serial twin-screw extruder unit and the packaging equipment. 7. The continuous manufacturing process according to claim 1, characterized in that: a filter is provided at the outlet of the twin-screw extruder.

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