CN103923298A - Two-component type production method of high heat resistance and high wear resistance polyurethane - Google Patents

Abstract

The invention relates to a two-liquid type preparation method of high heat-resistant and high wear-resistant Polyurethane (PU), which comprises the steps of mixing a hydroxyl-containing half-reaction polymer A liquid and an isocyanate-containing half-reaction polymer B liquid, carrying out secondary reaction, coating the mixture on a substrate through a coating machine, and curing the coating to form a PU synthetic film. The half-reacted polymers A and B were produced in advance by a preliminary polymerization reaction. The needed PU is polymerized by using a semi-reaction polymer A liquid and a semi-reaction polymer B liquid with new functionality and structure, and is matched with a coating machine to produce and synthesize the PU synthetic film with high heat resistance and high wear resistance under the environment of the reaction temperature of about 80 ℃. Or coating the base cloth to form the PU synthetic leather. The two-liquid type preparation method does not use a solvent as a carrier, and can solve the environmental protection problem of air and water pollution.

Description

Two-component type production method of high heat resistance and high wear resistance polyurethane

technical field

The present invention relates to a manufacturing method of polyurethane synthetic film/skin, and in particular to a solvent-free, non-thermosetting and non-single-component polyurethane manufacturing process. In this process, after pre-polymerizing half-reaction polymers A and B, the two liquids are mixed to form a liquid mixed solution, and the liquid mixed solution is solidified (about 30 minutes before the liquid mixed solution is solidified by coating machinery and equipment at about 80°C). ) Coating the liquid mixed solution onto the substrate to produce a polyurethane synthetic film/skin with high heat resistance and high wear resistance.

Background technique

Due to the increasing living standards and knowledge level of modern people, people's consumption demand for daily necessities (such as leather, etc.) is also relatively increasing. However, natural resources are limited, so it has gradually become a trend to replace real leather with synthetic leather imitation.

In the traditional synthetic leather production method, a polyurethane (PU) solution containing a solvent is coated on the substrate, and then the solvent is dried by heating to form a synthetic film after drying and curing the PU, or A synthetic skin is formed on the substrate. However, commonly used solvents for dissolving PU resins are dimethyl formamide (Dimethyl formamide, DMF), methyl ethyl ketone (methyl ethyl ketone) or toluene (xylene). In the traditional synthetic leather manufacturing method, the above-mentioned solvents are likely to cause serious air pollution and water pollution.

Furthermore, DMF has been shown to be associated with several human health disorders and is listed as a regulated solvent by environmental protection agencies in most countries around the world. In addition, there are still many deficiencies in the synthesis of PU synthetic films through traditional synthesis methods as follows:

1. In the traditional PU film synthesis method, in order to facilitate the coating operation, the PU resin needs to be dissolved or melted into a liquid state, so that the urethane bond in the PU resin must be destroyed first, resulting in insufficient mechanical strength of the product , It is easy to cause peeling, abrasion and flexibility that cannot meet the requirements of the high-end market.

2. In the traditional PU film synthesis method, the urethane bond in the produced PU film is not so good that its melting point cannot exceed 170°C. And because the mechanical strength of the PU film is insufficient, when the PU film is processed and sewn, after the bur rapidly rubs the PU film, powder particles will be produced at the seam.

3. In the traditional PU film synthesis method, the PU film is formed by drying and curing the PU solution, and the PU solution uses an organic solvent as the carrier, so the secondary processing can only be carried out after the first layer of film is completely dried and cured . It is impossible to carry out secondary processing while coating the first layer of PU, which causes inconvenience and restrictions on the back-end application.

4. In the traditional PU foam layer synthesis method, water drop-shaped holes will be formed inside the PU layer. The length of the pores is about 250 to 350 μm, and the width is about 150 to 320 μm. The holes with larger pore diameters are often generated close to the surface of the PU foam layer, and most of the holes are unevenly distributed.

5. In the traditional PU film synthesis method, a large amount of solvent is used, and the base material is mostly release paper, which is easily eroded by solvent, resulting in damage to the expensive release paper and increasing the cost.

Contents of the invention

In view of the problems and deficiencies of the above-mentioned traditional PU synthetic film/leather production method, the purpose of the present invention is to provide a two-component method for the production of polyurethane with high heat resistance and high wear resistance. It is a solvent-free, hydrolysis-resistant, heat-resistant and wear-resistant environmentally friendly blocking reactive PU resin.

In the two-component manufacturing method, the half-reacted polymer A liquid and the half-reacted polymer B liquid are first prepared by pre-polymerization, and the two liquids are mixed to form a liquid mixed solution. The above-mentioned liquid mixed solution is coated on the substrate by using the existing dry PU coating equipment, and the PU synthetic film/skin with high heat resistance and high wear resistance can be obtained after the liquid mixture is cured.

The PU synthetic skin/membrane produced by the two-component manufacturing method of the present invention has the characteristics of good wear resistance, high heat resistance and thermoplasticity. And the use of the two-component preparation method of the present invention can avoid the pollution of air and water sources in the environment during the manufacturing process, and the air pollution tax (collected by the government) can be exempted. Furthermore, the two-component manufacturing method is easy to operate, and both product quality and yield can be improved.

According to the purpose of the present invention, a two-liquid type production method of polyurethane with high heat resistance and high wear resistance is proposed, and its steps include pre-polymerizing half-reaction polymer A liquid containing hydroxyl groups and containing isocyanate groups half-reaction polymer B liquid, and adjust the ratio of the half-reaction polymer A liquid and the half-reaction polymer B liquid according to the physical property requirements of polyurethane products, and mix the half-reaction polymer A liquid and the half-reaction polymer B liquid in a vacuum state The half-reacted polymer B liquid forms a liquid mixed solution in a container to start the secondary reaction. Then, before the secondary reaction is completed, when the liquid mixed solution is still in a liquid state, the liquid mixed solution is coated on the substrate to form a coating. Finally, the coating is cured to form a PU synthetic film. Furthermore, the other side of the coating relative to the base material can be covered with a base cloth to form a PU synthetic leather.

The present invention also provides a two-component manufacturing method of high heat-resistant and high wear-resistant polyurethane. The two-component manufacturing steps include:

Step 1: Take the required polyurethane raw materials in advance, including half-reacted polymer A liquid and half-reacted polymer B liquid, and adjust the half-reacted polymer A liquid and half-reacted polymer liquid according to the physical properties of polyurethane products. After reacting the ratio of polymer B liquid, pour it into a container and mix to form a liquid mixed liquid to start the secondary reaction;

Step 2: Cooperate with the existing dry polyurethane coating equipment, before the secondary reaction is completed and the liquid mixed solution is completely solidified, mix the liquid formed by mixing the half-reacted polymer A liquid with the half-reacted polymer B liquid The solution is sent to the coating equipment through the pipeline and coated on the substrate to form a coating;

Step 3: After the coating on the substrate is cured, a polyurethane synthetic film can be formed. And when the surface of the coating on the base material is cured, the base material and the polyurethane synthetic film can be rolled up to save the production time of the process.

In a preferred embodiment, the half-reaction polymer A liquid is formed by copolymerization of a polyester, a diisocyanate, a hydroxyl chain extender and a polyether under a delayed reaction catalyst, and contains isocyanic acid The base half-reaction polymer solution B is formed by copolymerization of a polyadipate, a polyether polyol and a diisocyanate, and part of the isocyanate group is blocked by a blocking agent.

In a preferred embodiment, the delayed reaction catalyst is a blocking catalyst or an amine catalyst.

In a preferred embodiment, the substrate is a release paper.

In a preferred embodiment, the two-component manufacturing method further includes, before the coating is cured, coating a base cloth on the other side of the coating relative to the substrate to form a polyurethane synthetic skin .

In a preferred embodiment, when coating the liquid mixed solution, a dry gas is injected to make the polyurethane synthetic film form a foam layer.

In a preferred embodiment, the drying gas is nitrogen, carbon dioxide or a gas generated by spores.

In a preferred embodiment, when coating the liquid mixed solution, a heater is provided to prolong the curing time of the coating.

In the two-component manufacturing method of the present invention, the pre-polymerized half-reacted polymer liquid A and the half-reacted polymer liquid B can solve the problems of solvent pollution and energy waste in the traditional manufacturing method. In addition, the bonding structure of the prepared PU synthetic film/skin is relatively stable and complete.

Based on the above, the two-component method for producing high heat-resistant and highly wear-resistant polyurethane of the present invention has at least the following advantages:

1. In the two-liquid type production method of the present invention, half-reaction polymers A and B liquids are formed by pre-polymerization of blocked PU raw materials, without using solvents (such as dimethylformamide) as carriers, which can solve the problem of existing solvents Environmental issues such as air and water pollution caused by the PU process.

2. In the two-component method of the present invention, after the half-reaction polymers A and B are mixed, a secondary reaction will be carried out. When the liquid mixed solution is in a liquid state, it is coated on the substrate by a coating machine to form a coating, and then the coating is cured to form a PU synthetic film. The operation time of the two-component method is shorter than that of the existing solvent-based process, and saves the cost of heat-drying equipment for drying the solvent in the existing process. Therefore, it can avoid long-term waiting for the solvent to dry, and is more efficient.

3. The two-component manufacturing method of the present invention is different from the existing one-shot manufacturing process. In the one-component manufacturing process, multiple raw materials are charged at one time and only a single urethane bonding reaction (polymerization reaction) is performed. The preparation method of the two-liquid type of the present invention is to pre-polymerize half-reaction polymers A and B liquids in advance, and its components contain blocked sodium methyl isocyanate. The excess unreacted isocyanate groups in the half-reacted polymers A and B liquids continue to react with hydroxyl compounds, and the final esterification reaction is completed under the action of a delayed catalyst. Since no heat source is used in the process, fires can be prevented. And because there is no solvent residue in the finished product, the health and safety of operators can be improved.

4. In the two-liquid type production method of the present invention, the PU synthetic film is formed by mixing and reacting half-reacted polymers A and B in the correct proportion in advance. Its operation is relatively simple, and the precision of mechanical operation is much higher than that of the existing one-unit component manufacturing process, which can reduce labor costs (including not requiring extremely high-end professional and technical personnel to be competent), and can increase the yield rate of finished products. The current process of one unit component (or single batch feeding) requires multiple raw materials (more than three or more) to be fed at one time and only one reaction is performed. Therefore, the requirements for personnel, technology, equipment and equipment are extremely high to ensure accurate operation and avoid human error. This leads to high risk and instability in the production of one-unit component process, and it is difficult to improve the yield rate of finished products.

5. In the two-liquid type preparation method of the present invention, it is to pre-polymerize the half-reaction polymer A and B liquids, and then mix the two at a predetermined ratio, and it can be used in conjunction with existing dry PU coating equipment, reducing Additional costs for machinery and equipment.

6. In the two-component method of the present invention, the factor affecting the hardness of the PU synthetic film/skin is the mixing ratio of the semi-reactive polymer A and liquid B, and its hardness can be between ASTM D2240 standard Shore 30A to Room 95A.

7. In the two-component manufacturing method of the present invention, the elasticity of the PU synthetic film/leather product can also be adjusted through the mixing ratio of the semi-reactive polymer A and liquid B.

8. In the two-component preparation method of the present invention, high molecular weight half-reaction polymers A and B are formed due to pre-bonding. After the two liquids are mixed, a higher molecular weight PU synthetic film can be formed through a secondary reaction (or polymerization reaction) to improve the toughness, hardness, hydrolysis resistance and heat resistance of the PU synthetic film. Different from the traditional solvent-based production method, it will destroy the urethane bond in the PU resin and reduce the molecular weight.

9. In the two-component manufacturing method of the present invention, when the semi-reactive polymers A and B are mixed, the liquid mixed solution starts to solidify immediately. Subsequent processing can be carried out at the same time as the first coating, so as to increase the application field of the two-component manufacturing method of the present invention.

Description of drawings

Fig. 1 is a flow chart showing the steps of the two-component manufacturing method of the high heat-resistant and high wear-resistant polyurethane of the present invention;

Fig. 2 is a schematic diagram illustrating a two-component method for producing a high heat-resistant and high wear-resistant polyurethane according to an embodiment of the present invention;

Fig. 3 is a schematic diagram illustrating a two-component manufacturing method of high heat-resistant and high wear-resistant polyurethane according to another embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating a two-component manufacturing method of high heat-resistant and high-wear polyurethane according to another embodiment of the present invention.

Description of main component symbols

1, 1': Semi-reactive polymer liquid A 2, 2': Semi-reactive polymer liquid B

3: Vacuum mixer 4, 4': Coating machine

5: Substrate 6: Heater

7, 7': base cloth 71, 71': rolling wheel

S1～S3: steps

Detailed ways

Please refer to Fig. 1 and Fig. 2, wherein Fig. 1 is a flow chart showing the steps of the two-component method for producing high heat-resistant and high-abrasion polyurethane of the present invention, and Fig. 2 is a flowchart of the present invention A schematic diagram of a two-component method for producing high heat-resistant and highly wear-resistant polyurethane according to an embodiment. In the two-liquid type production method of the present invention, the half-reacted polymer A liquid 1 and the half-reacted polymer B liquid 2 are first produced through prepolymerization, and then the two liquids are mixed to form a liquid mixed solution for secondary reaction. There is about 30 minutes of operating time before the liquid mixed solution is solidified. During this time, the liquid mixed solution is still in a liquid state, and it is convenient to apply the liquid mixed solution to the substrate by a dry PU coating machine.

1: Semi-reactive polymer liquid A

The above-mentioned half-reaction polymer A liquid 1 is formed after pre-polymerization reaction of blocked PU raw materials. Blocking PU raw materials include polyester, diisocyanate, hydroxyl chain extender and polyether. The blocked PU raw material is copolymerized under the action of a delayed reaction catalyst to form half-reaction polymer A liquid 1. And after the above-mentioned copolymerization reaction, anti-UV agents, heat-resistant agents, antioxidants, defoamers and other additives can be further added according to the requirements of the final PU synthetic film.

The above-mentioned polyester is formed by jointly esterifying ethylene glycol, hexanediol, dichlorobenzene, butanediol, trimethylpropane, acid anhydride and dibasic acid.

The above-mentioned polyether is formed by the joint reaction of propylene glycol, polyethylene glycol, ethylene oxide and propylene oxide.

The above-mentioned hydroxyl chain extender is diethylene glycol, ethylene glycol, propylene glycol, trimethylpropane or pentaerythritol.

The above-mentioned diisocyanate is generated by the reaction of dichlorobenzene and cyclohexane diisocyanate.

The above-mentioned delayed reaction catalyst is a blocking catalyst or an amine catalyst.

2: half-reaction polymer liquid B

The above half-reaction polymer B liquid 2 is formed by pre-polymerization of blocked PU raw materials, wherein the blocked PU raw materials include polyadipate (polycaprolactone, PCL), polyether polyol (Polyether Polyol), diisocyanate (such as benzene Methane diisocyanate (methylene diphenyldi-isocyanate, MDI)) and blocking agent (Block Agent). The blocked PU raw material generates half-reaction polymer B liquid 2 through copolymerization. After the copolymerization reaction, a part of the isocyanate group is exposed, and another part of the isocyanate group will block the reaction with the blocking agent.

PU prepolymers with isocyanate groups, such as isocyanate or similar, can be used in two-component systems to produce chain extension or crosslinking reactions with PU prepolymers with hydroxyl groups. In addition, the amine-based component can react with isocyanate during the process to produce amine- or isocyanate-based nitrogen-containing prepolymers.

After the prepolymerization, the high molecular weight half-reacted polymer A solution 1 contains hydroxyl groups (OH), while the high molecular weight half-reacted polymer B solution 2 contains isocyanate groups (NCO). The required PU is polymerized with new functional and structural pre-polymerized intermediate products (such as polymer A liquid 1 and B liquid 2), thereby forming a higher molecular weight PU synthetic film, which has better Excellent toughness, hardness, hydrolysis resistance and heat resistance.

The functional group of the pre-polymerized intermediate product, such as the hydroxyl end of the half-reacted polymer A solution 1 and the isocyanate group end of the half-reacted polymer B solution 2, can be designed and planned in advance so that the functional group is pre-catalyzed by the chemical catalyst block. The action time of the secondary reaction (polymerization reaction) can be regulated by the delayed reaction catalyst. In the two-component manufacturing method of the present invention, the PU synthetic film structure obtained through prior design and planning is more stable than the PU synthetic film structure produced by the traditional process.

Two liquid type preparation method steps of the present invention are as follows:

S1 Mixing: Take the required PU raw materials in advance, including half-reacted polymer A liquid 1 and half-reacted polymer B liquid 2, and adjust half-reacted polymer A liquid 1 and half-reacted polymer B liquid according to the physical properties of PU products 2 After the ratio, pour it into a container, such as a vacuum mixer 3, and mix to form a liquid mixed solution to start the secondary reaction.

S2 coating: Cooperate with the existing dry PU coating equipment, before the secondary reaction is completed and the liquid mixed solution is completely solidified, the liquid mixed solution formed by mixing the half-reacted polymer A liquid 1 and the half-reacted polymer B liquid 2 , transported to the coating machine 4 through the pipeline 41 and coated on the substrate 5 to form a coating. The base material 5 is, for example, a release paper. During the coating step, coloring materials can also be added according to the color requirements of PU products.

S3 curing: after the coating on the substrate 5 is cured, a PU synthetic film can be formed. And when the coating surface on the base material 5 is solidified, the base material 5 and the PU synthetic film can be rolled up to save the production time of the process.

In the two-component manufacturing method of the present invention, during the coating step (S2), the heater 6 can be used to maintain the temperature of the coating, so as to prolong the time for the coating to solidify and form a film. The heater 6 can be added to the process during the coating step (S2) or the curing step (S3). Prolonging the curing time can make the bond between the half-reacted polymer A liquid 1 and the half-reacted polymer B liquid 2 more stable, and also provide enough time for setting up other subsequent processes.

The two-component manufacturing method of the present invention may also include a recovery step to recover the substrate 5 (such as release paper). After the curing step (S3), after the PU product is completely cured, the release paper and the PU synthetic film are separated and rolled up respectively.

FIG. 3 is a schematic diagram illustrating a two-component manufacturing method of high heat-resistant and high-wear polyurethane according to another embodiment of the present invention. In this embodiment, during the curing step, before the coating is cured, the base cloth 7 can be coated on the other side of the coating with respect to the base material 5 by the roller 71 . And part coating can penetrate in the fiber of base cloth 7 to form PU synthetic leather.

FIG. 4 is a schematic diagram illustrating a two-component manufacturing method of high heat-resistant and high-wear polyurethane according to another embodiment of the present invention. It is the manufacturing process of multi-layer PU synthetic film. The second liquid mixed solution formed by mixing half-reacted polymer A liquid 1' with half-reacted polymer B liquid 2' is applied to the aforementioned coating step (S2) and curing step (S3) with a second coating machine 4' ) on the formed first coating to form a second coating. After both coatings are cured, a multi-layer PU synthetic film is formed. In addition, the rolling wheel 71' and the rolling base cloth 7' can also be used on the second coating layer during the manufacturing process. The steps are the same as those in the above-mentioned embodiment, so they will not be repeated here.

In the above-mentioned multi-layer PU synthetic film process, during the coating step (S2), a manifold can be installed in the pipeline 41' to inject dry gas into the coating, and use the gas to form air pockets to make the coating The PU synthetic film on the release paper forms a foam layer. The aforementioned drying gas is, for example, nitrogen, carbon dioxide, or a gas produced by spores.

The above description is for illustration only, not for limitation. Any equivalent modifications or changes made without departing from the spirit and scope of the present invention shall be included in the claims.

Claims (10)

1. A two-component manufacturing method of high heat-resistant and highly wear-resistant polyurethane, characterized in that it comprises: Pre-polymerize the half-reaction polymer A liquid containing hydroxyl groups and the half-reaction polymer B liquid containing isocyanate groups, and adjust the half-reaction polymer A liquid and the half-reaction polymerization according to the physical property requirements of polyurethane products The ratio of the substance B liquid, and mixed the half-reacted polymer A liquid and the half-reacted polymer B liquid in a container in a vacuum state to form a liquid mixed solution to start the secondary reaction; Before the secondary reaction is completed, when the liquid mixed solution is still in a liquid state, coating the liquid mixed solution on a substrate to form a coating; curing the coating to form a polyurethane synthetic film; Thus, the bonding structure of the polyurethane synthetic film is more solid and complete, and the operation is convenient so as to be easy to produce a high heat-resistant and high wear-resistant polyurethane synthetic film. 2. The two-component preparation method as claimed in claim 1, wherein the semi-reactive polymer A liquid is composed of a polyester, a diisocyanate, a hydroxyl chain extender and a polyether in a It is formed by copolymerization under a delayed reaction catalyst, and the half-reaction polymer B liquid containing isocyanate group is formed by copolymerization of a polyadipate, a polyether polyol and a diisocyanate, and Part of the isocyanate group is blocked by a blocking agent. 3. The two-component manufacturing method according to claim 2, wherein the delayed reaction catalyst is a blocking catalyst or an amine catalyst. 4. The two-component manufacturing method according to claim 1, wherein the substrate is a release paper. 5. The two-component manufacturing method according to claim 1, further comprising, before the surface of the coating is cured, coating a base cloth on the other side of the coating relative to the substrate to form a Polyurethane synthetic leather. 6 . The two-component manufacturing method according to claim 1 , wherein when coating the liquid mixed solution, a dry gas is poured into the polyurethane synthetic film to form a foam layer. 7 . 7 . The two-component manufacturing method according to claim 6 , wherein the dry gas is nitrogen, carbon dioxide or a gas produced by spores. 8 . 8 . The two-component manufacturing method according to claim 1 , wherein a heater is provided when coating the liquid mixed solution to prolong the curing time of the coating. 9. A two-component manufacturing method of high heat-resistant and highly wear-resistant polyurethane, the two-component manufacturing steps comprising: Step 1: Take the required polyurethane raw materials in advance, including half-reacted polymer A liquid and half-reacted polymer B liquid, and adjust the half-reacted polymer A liquid and half-reacted polymer liquid according to the physical properties of polyurethane products. After reacting the ratio of polymer B liquid, pour it into a container and mix to form a liquid mixed liquid to start the secondary reaction; Step 2: Cooperate with the existing dry polyurethane coating equipment, before the secondary reaction is completed and the liquid mixed solution is completely solidified, mix the liquid formed by mixing the half-reacted polymer A liquid with the half-reacted polymer B liquid The solution is sent to the coating equipment through the pipeline and coated on the substrate to form a coating; Step 3: After the coating on the substrate is cured, a polyurethane synthetic film can be formed; and when the surface of the coating on the substrate is cured, the substrate and the polyurethane synthetic film can be rolled Put it aside. 10. The two-component preparation method as claimed in claim 9, wherein the half-reaction polymer A liquid is composed of a polyester, a diisocyanate, a hydroxyl chain extender and a polyether in a It is formed by copolymerization under a delayed reaction catalyst, and the half-reaction polymer B liquid containing isocyanate group is formed by copolymerization of a polyadipate, a polyether polyol and a diisocyanate, and Part of the isocyanate group is blocked by a blocking agent.