CN111809405A - A kind of preparation method of reactive compatibilizer for polyurethane-organosilicon synthetic leather coating - Google Patents

Abstract

The invention discloses a preparation method of a reactive compatibilizer for polyurethane-organosilicon synthetic leather coatings. Using the coordination addition reaction of silicon-hydrogen bond and double bond, a kind of reactive compatibilizer with silicon-hydrogen bond was synthesized by grafting polyethylene glycol allyl methyl ether on the side chain of hydrogen-containing silicone oil. And it was used for compatibilization of polyurethane-silicon interpenetrating network coating system. The reactive compatibilizer prepared by the invention has a "mutual solubility" effect between the organic silicon and the polyurethane, and can effectively reduce the interfacial tension between the two phases of the polyurethane and the organic silicon, thereby improving the compatibility. Compared with the pre-compatibilized polyurethane-silicon coating, the mutual compatibility of the two is improved, the degree of phase separation is reduced, the interpenetrating network is easier to form, and the mechanical properties and surface polarity of the coating are significantly improved. In addition, no solvent is used in the preparation process of the compatibilizer, which realizes the greening of the preparation process.

Description

A kind of preparation method of reactive compatibilizer for polyurethane-organosilicon synthetic leather coating

technical field

The invention relates to a preparation method of a reactive compatibilizer for polyurethane-organosilicon synthetic leather coating, and belongs to the field of polymer material modification.

Background technique

As a kind of chemical material that is not dependent on petrochemical resources, silicone has been used in textile auxiliaries, automobiles, It is widely used in daily chemical, biomedical and other industries. With the development of the silicone industry, silicone resins based on solvent-free two-component hydrosilylation systems have entered the fields of textiles and synthetic leather coatings. For example, Chinese patent CN205688265U discloses an ultra-soft silicone leather, which includes a first silicone rubber layer, a second silicone rubber layer, an ultra-soft silicone rubber layer and a substrate arranged in sequence from top to bottom, giving the leather the characteristics of soft and plump texture . However, although silicone coatings have many advantages, due to their own structural characteristics, when used as coating materials such as synthetic leather, they often have insufficient mechanical strength (tensile strength ≤ 5MPa, elongation ≤ 400% ), low surface tension, and poor adhesion to the substrate limit its further development and application in the field of synthetic leather. Therefore, it has become a research hotspot to develop a composite material that not only possesses the excellent properties of silicone, but also takes into account or satisfies the properties required for synthetic leather coating materials.

Polyurethane is a kind of polar polymer material containing repeating urethane bond structure (-NHCOO-) formed by polyaddition reaction of polyisocyanate and polyol (including polyester polyol and polyether polyol). . Polyurethane resin can be regarded as a block copolymer in which soft segments and hard segments are alternately connected. Among them, the soft segment determines the adhesion and elongation at break of the resin, and the hard segment determines the modulus, strength and other properties of the resin. The molecular chain often contains ester groups, ether groups, urea bonds, urethane polar groups such as ester bonds. Because of its unique structure, polyurethane resin has many excellent properties, such as excellent mechanical properties, adhesion and a wide range of softness and hardness, and is widely used in synthetic leather coatings. Therefore, it is also very suitable for modifying silicone coating materials. For example, Chinese patent CN109722917A discloses a method for improving the surface tension and recoatability of organic silicon synthetic leather coating. The double bond-terminated polar polyurethane segment is introduced into the silicone synthetic leather coating material by the coordination addition reaction between the silicon hydrogen bond and the double bond, which improves the surface tension and recoatability of the silicone synthetic leather coating. It effectively solves the technical problems of poor adhesion to the base fabric, wetting and leveling after finishing, and poor recoatability caused by the low surface energy of a single organosilicon synthetic leather coating. The introduction of polyurethane into silicone can realize the complementary advantages of silicone and polyurethane material properties. While retaining the excellent properties of the silicone coating, it can effectively make up for its deficiencies in mechanical properties, surface tension, and adhesion to the substrate. .

However, due to the large differences in chemical structure and polarity between silicone and polyurethane, direct mixing of the two often leads to delamination due to poor compatibility. to the intended purpose.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a preparation method of a reactive compatibilizer for a polyurethane-organosilicon synthetic leather coating against the deficiencies of the above-mentioned prior art. Using the coordination addition reaction between the silicon-hydrogen bond in hydrogen-containing polysiloxane and the double bond in polyethylene glycol allyl methyl ether, the semi-polar polyether side chain is grafted into hydrogen-containing polysiloxane to prepare A reactive compatibilizer was developed and used in the compatibilization of polyurethane-silicon interpenetrating network coating systems.

The invention provides a method for preparing a reactive compatibilizer for a polyurethane-organosilicon synthetic leather coating, which is characterized in that it comprises the following steps, and the parts of the materials used are all parts by weight:

(1) Preparation of reactive compatibilizer:

Add 6 to 20 parts of hydrogen-containing polysiloxane and 6 to 30 parts of polyethylene glycol allyl methyl ether into the reaction kettle, and control the molar ratio of the system-C=C/Si-H to be 0.3 to 0.6. The temperature was raised to 85 °C, 1~2 parts of chloroplatinic acid catalyst was added under stirring, and the reaction was carried out at 100~120 °C for 1~2 h to obtain a reactive compatibilizer containing polyethylene glycol side chains;

(2) Preparation of polyurethane-silicon synthetic leather coating:

60-95 parts of vinyl polysiloxane, 1-7 parts of hydrogen-containing polysiloxane, 2-5 parts of liquid diisocyanate, 20-45 parts of liquid polyol, 0-0.2 parts of organic bismuth catalyst, (1 ) prepared reactive compatibilizer 2~8 parts, chloroplatinic acid catalyst 1~2 parts, methyl butynol 0.2~0.4 parts, white carbon black 10~20 parts were quickly mixed at room temperature, and then the mixture was injected and coated Covered on the surface of the release paper, reacted in an oven at 120-130 °C for 8-10 min, and then transferred to the surface of the base fabric for lamination, and further cured to obtain a solvent-free polyurethane-organic silicon synthetic leather coating.

The method for preparing a reactive compatibilizer for a polyurethane-organosilicon synthetic leather coating is characterized in that the hydrogen-containing polysiloxane described in the method is a hydrogen-containing polysiloxane with a hydrogen content of 0.8 to 1.6%. Silicone oil, the hydrogen atoms are located in the side chains of polysiloxanes.

The method for preparing a reactive compatibilizer for a polyurethane-organosilicon synthetic leather coating is characterized in that the molecular weight of the polyethylene glycol allyl methyl ether is 290-1000 g/mol, and the structure is the same. The formula is: CH ₂ =CHCH ₂ O(CH ₂ CH ₂ O) _n CH ₃ , where n=5~20.

The preparation method of described a kind of polyurethane-organic silicon synthetic leather coating reactive type compatibilizer, it is characterized in that described vinyl polysiloxane is double-ended vinyl silicone oil (vinyl content: 0.05～0.43% , the general structural formula is: CH ₂ =CH(CH ₃ ) ₂ Si-O-[(CH ₃ ) ₂ Si-O] _n Si(CH ₃ ) ₂ CH=CH ₂ , where n=200~3000), many One or a combination of vinyl silicone oil (vinyl content: 0.2~2.3 %, vinyl is mainly located in branched chain).

The method for preparing a reactive compatibilizer for a polyurethane-organosilicon synthetic leather coating is characterized in that the liquid diisocyanate is hexamethylene diisocyanate, isophorone diisocyanate, 4,4 - One or a combination of dicyclohexylmethane diisocyanate, 2,4-toluene diisocyanate, and diphenylmethane diisocyanate (MDI-50).

The method for preparing a reactive compatibilizer for a polyurethane-organosilicon synthetic leather coating is characterized in that the liquid polyhydric alcohol is polyethylene glycol with a number-average molecular weight of 600-1000 and a number-average molecular weight of 1000. One or a combination of polypropylene glycol of ~4000 and poly(1,3-butanediol adipate) with a number average molecular weight of 1000 to 2000.

Compared with the prior art, the present invention has the following positive effects:

(1) In the present invention, a reactive compatibilizer is synthesized by grafting polyethylene glycol allyl methyl ether on the side chain of hydrogen-containing polysiloxane, which effectively solves the problem of polar polyurethane components and non-polar polyamides. The phase separation problem of the siloxane components in the process of mixing and reaction, and the preparation process of the compatibilizer does not require any solvent, which meets the requirements of green and environmental protection;

(2) The reactive compatibilizer prepared by the present invention can be covalently bonded to the polymer coating during the curing process while playing a compatibilizing effect, so that the compatibilized polyurethane-organosilicon interpenetrating network can be obtained. The coating system is more stable, and also has the function of plasticizing and softening the coating;

(3) The reactive compatibilizer prepared by the present invention can effectively reduce the interfacial tension between the silicone and the polyurethane, realize the fusion of the two at the molecular level, and make the mechanical properties, surface tension, and The adhesion performance of the substrate is significantly improved.

Detailed ways

The present invention will be specifically described below through the examples. It is necessary to point out that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Those skilled in the art can Some non-essential improvements and adjustments are made to the content, which still belong to the protection scope of the present invention.

Example 1:

(1) Preparation of reactive compatibilizer:

20 parts of hydrogen-containing polysiloxanes with a hydrogen content of 0.8% and 6 parts of polyethylene glycol allyl methyl ethers with a molecular weight of 360 g/mol were added to the reactor, and the control system-C=C/Si The molar ratio of -H was 0.5, the temperature was raised to 85 °C, 1 part of chloroplatinic acid catalyst was added under stirring, and the reaction was carried out at 100 °C for 1 h to obtain a reactive compatibilizer containing polyethylene glycol side chains;

(2) Preparation of polyurethane-silicon synthetic leather coating:

80 parts of double-ended vinyl silicone oil with a vinyl content of 0.12%, 12 parts of polyvinyl silicone oil with a vinyl content of 2.3%, 7 parts of hydrogen-containing silicone oil with a hydrogen content of 0.18%, and 2 isophorone diisocyanate parts, 10 parts of polypropylene glycol (PPG2000) with a number average molecular weight of 2000, 10 parts of polypropylene glycol (PPG3000) with a number average molecular weight of 3000, 0.2 parts of organic bismuth catalyst, 2 parts of reactive compatibilizer prepared from (1), chloroplatinic acid 1 part of catalyst, 0.2 part of methylbutynol, and 10 parts of white carbon black were quickly mixed at room temperature, and then the mixture was injected and coated on the surface of the release paper, reacted in an oven at 120 °C for 8 min, and then transferred to the surface of the base cloth After lamination and further curing, a solvent-free polyurethane-organosilicon synthetic leather coating is obtained.

After testing, compared with the polyurethane modified silicone coating before compatibilization, the tensile strength of the coating after compatibilization increased from 4.2 MPa to 6.5 MPa, and the elongation at break increased from 380 % to 560 %. Compared with the single organosilicon coating before modification, the surface energy of the coating increased from 22 mJ/m ² to 30 mJ/m ² , the water contact angle decreased from 131° to 108°, and the peel strength between the coating and the base fabric decreased from 131° to 108°. 39 N/3 cm raised to 51 N/3 cm.

Example 2:

(1) Preparation of reactive compatibilizer:

The hydrogen content is 10 parts of hydrogen-containing polysiloxanes of 1.0%, and the molecular weight is 24 parts of polyethylene glycol allyl methyl ethers of 512 g/mol, added in the reactor, and the control system-C=C/Si The molar ratio of -H was 0.6, the temperature was raised to 85 °C, 1 part of chloroplatinic acid catalyst was added under stirring, and the reaction was carried out at 110 °C for 1.5 h to obtain a reactive compatibilizer containing polyethylene glycol side chains;

(2) Preparation of polyurethane-silicon synthetic leather coating:

45 parts of double-terminated vinyl silicone oil with a vinyl content of 0.07%, 30 parts of double-terminated vinyl silicone oil with a vinyl content of 0.43%, 20 parts of polyvinyl silicone oil with a vinyl content of 1.4%, and a hydrogen content of 1.6 parts 1 part of hydrogen-containing silicone oil, 4 parts of hexamethylene diisocyanate, 15 parts of polyethylene glycol (PEG1000) with a number average molecular weight of 1000, 20 parts of polypropylene glycol (PPG2000) with a number average molecular weight of 2000, and 0.1 part of organic bismuth catalyst , (1) 4 parts of the prepared reactive compatibilizer, 1.5 parts of chloroplatinic acid catalyst, 0.3 part of methyl butynol, and 15 parts of white carbon black were quickly mixed at room temperature, and then the mixture was injected and coated on release paper. The surface was reacted in an oven at 120 °C for 8 min, and then transferred to the surface of the base fabric for lamination. After further curing, a solvent-free polyurethane-organic silicon synthetic leather coating was obtained.

After testing, compared with the polyurethane modified silicone coating before compatibilization, the tensile strength of the compatibilized coating increased from 4.6 MPa to 8 MPa, and the elongation at break increased from 360 % to 550 %. Compared with the single organosilicon coating before modification, the surface energy of the coating increased from 22 mJ/m ² to 36 mJ/m ² , the water contact angle decreased from 131° to 97°, and the peel strength between the coating and the base fabric decreased from 131° to 97°. 39N/3 cm raised to 56 N/3 cm.

Example 3:

(1) Preparation of reactive compatibilizer:

6 parts of hydrogen-containing polysiloxane with a hydrogen content of 1.6% and 30 parts of polyethylene glycol allyl methyl ether with a molecular weight of 1000 g/mol were added to the reactor, and the control system-C=C/Si The molar ratio of -H was 0.3, the temperature was raised to 85 °C, 2 parts of chloroplatinic acid catalyst were added under stirring, and the reaction was carried out at 120 °C for 2 h to obtain a reactive compatibilizer containing polyethylene glycol side chains;

(2) Preparation of polyurethane-silicon synthetic leather coating:

40 parts of di-terminal vinyl silicone oil with a vinyl content of 0.15%, 20 parts of polyvinyl silicone oil with a vinyl content of 1.4%, 3 parts of hydrogen-containing silicone oil with a hydrogen content of 0.18%, 5 parts of toluene diisocyanate, 15 parts of polyethylene glycol (PEG1000) with an average molecular weight of 1000, 30 parts of poly(1,3-butanediol adipate) diol (PMA2000) with a number average molecular weight of 2000, 0 parts of organic bismuth catalyst, (1) Preparation 8 parts of reactive compatibilizer, 2 parts of chloroplatinic acid catalyst, 0.4 part of methylbutynol, and 20 parts of white carbon black were quickly mixed at room temperature, and then the mixture was injected and coated on the surface of the release paper, at 130 ℃ The reaction was carried out in an oven for 10 min, and then transferred to the surface of the base fabric for lamination. After further curing, a solvent-free polyurethane-organosilicon synthetic leather coating was obtained.

After testing, compared with the polyurethane modified silicone coating before compatibilization, the tensile strength of the compatibilized coating increased from 4.8 MPa to 9 MPa, and the elongation at break increased from 350 % to 600 %. Compared with the single silicone coating before modification, the surface energy of the coating increased from 22 mJ/m ² to 39.2 mJ/m ² , the water contact angle decreased from 131° to 89°, and the peel strength of the coating and the base fabric decreased from 131° to 89°. 39 N/3 cm raised to 64 N/3 cm.

Claims (6)

1. A preparation method of a reactive compatibilizer for a polyurethane-organic silicon synthetic leather coating is characterized by comprising the following steps of:

(1) preparation of reactive compatibilizer:

adding 6-20 parts of hydrogen-containing polysiloxane and 6-30 parts of polyethylene glycol allyl methyl ether into a reaction kettle, controlling the molar ratio of-C = C/Si-H of a system to be 0.3-0.6, heating to 85 ℃, adding 1-2 parts of chloroplatinic acid catalyst under stirring, and reacting at 100-120 ℃ for 1-2 hours to prepare a reactive compatibilizer containing a polyethylene glycol side chain;

(2) preparing a polyurethane-organic silicon synthetic leather coating:

60-95 parts of vinyl polysiloxane, 1-7 parts of hydrogen-containing polysiloxane, 2-5 parts of liquid diisocyanate, 20-45 parts of liquid polyol, 0-0.2 part of organic bismuth catalyst, 2-8 parts of the prepared reactive compatibilizer (1), 1-2 parts of chloroplatinic acid catalyst, 0.2-0.4 part of methyl butynol and 10-20 parts of white carbon black are quickly mixed at normal temperature, then the mixture is injected and coated on the surface of release paper, the mixture is reacted in an oven at 120-130 ℃ for 8-10 min, then the mixture is transferred to the surface of base cloth for bonding, and the solvent-free polyurethane-organosilicon synthetic leather coating is obtained after further curing.

2. The method for preparing the reactive compatibilizer for the polyurethane-organic silicon synthetic leather coating according to claim 1, wherein the hydrogen-containing polysiloxane is hydrogen-containing silicone oil with the hydrogen content of 0.8-1.6%, and the hydrogen atoms are positioned on the side chain of the polysiloxane.

3. The preparation method of the reactive compatibilizer for the polyurethane-organic silicon synthetic leather coating according to claim 1, wherein the molecular weight of the polyethylene glycol allyl methyl ether is 290-1000 g/mol, and the general structural formula is as follows: CH (CH)₂=CHCH₂O(CH₂CH₂O)_nCH₃Wherein n =5~ 20.

4. The method for preparing the reactive compatibilizer for polyurethane-organic silicon synthetic leather coating according to claim 1, wherein the vinyl polysiloxane is double-ended vinyl silicone oil (vinyl content: 0.05-0.43%, structural general formula: CH)₂=CH(CH₃)₂Si-O-[(CH₃)₂Si-O]_nSi(CH₃)₂CH=CH₂Wherein n =200 to 3000), polyvinyl silicone oil (vinyl content: 0.2-2.3% of vinyl, mainly located in a branched chain).

5. The method for preparing the reactive compatibilizer for polyurethane-silicone synthetic leather coating according to claim 1, wherein the liquid diisocyanate is one or a combination of hexamethylene diisocyanate, isophorone diisocyanate, 4-dicyclohexylmethane diisocyanate, 2, 4-toluene diisocyanate and diphenylmethane diisocyanate (MDI-50).

6. The method for preparing the reactive compatibilizer for polyurethane-organic silicon synthetic leather coating according to claim 1, wherein the liquid polyalcohol is one of polyethylene glycol with number average molecular weight of 600-1000, polypropylene glycol with number average molecular weight of 1000-4000, poly adipic acid-1, 3-butanediol glycol with number average molecular weight of 1000-2000 or a combination thereof.