JPH10324730A - Polyurethane resin reaction product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyurethane resin reaction product having silicone side chains by one step reaction comprising reacting an alcohol-modified dimethyl siloxane with an isocyanate group-monomer. SOLUTION: (A) A polydimethylsiloxane of formula I [R<1> is a 1-4C alkyl; R<2> is ethylene, etc.; R<3> is H, etc.; R<4> is hydroxyl, etc.; (n) is 0-100; (p) is 0-100; (m) is 2-9] having an alkyl group on one end side and two hydroxyl groups on the end side is reacted with (B) a polyisocyanate of formula II [Et is ethyl; R<5> is (CH2 )6 , etc.] having two or more isocyanate groups in the molecule as essential components to obtain the polyurethane resin reaction product having polydimethylsiloxane side chains and isocyanate groups in the polyurethane molecule main chain. Since the silicone compound is chemically bound, the silicone compound is not bled out, and since the reaction product has the isocyanate groups, the reaction product can variously chemically be modified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane resin reactant having a polydimethylsiloxane side chain and an isocyanate group in a polyurethane molecular main chain, and more specifically, to uses such as paints, binders, adhesives and sealants. The present invention relates to a polydimethylsiloxane-modified urethane resin reactant having improved lubricity, water repellency, mold release properties, and the like, which is useful for the above.

[0002]

2. Description of the Related Art A polyurethane resin is a resin produced by reacting a resin or monomer having a hydroxyl group in a molecule with a resin or monomer having an isocyanate group in a molecule. It is widely used in paint binders, ink bases, adhesives, sealants, etc. because of its excellent properties, film forming properties, and dispersibility of pigments and the like.

[0003] Further, in order to better suit these uses or to further expand the range of use besides these uses, the polyurethane resin is modified by adding silicone to improve release properties, slip properties, water repellency and the like. Providing a property has been conventionally studied.

As a method of modifying a polyurethane resin with silicone, there is generally used a method of producing a silicone oil-modified polyurethane resin by reacting (a) a resin containing a hydroxyl group simply mixed with dimethyl silicone oil with a resin containing isocyanate. And (b) a method of producing a silicone-modified polyurethane resin by copolymerizing them using a hydroxyl group-containing monomer, an isocyanate group-containing monomer, and a polymerizable functional group-containing dimethyl silicone, and (C) a method of producing a silicone-modified polyurethane resin by grafting a reactive silicone having a functional group such as an isocyanate group which easily reacts with a hydroxyl group to a hydroxyl group remaining in the polyurethane resin.

However, according to the method (a), since the compatibility between dimethylsiloxane and other components is small, when this modified polyurethane resin is applied, the resulting film becomes opaque or the surface state becomes smooth. There is no problem. Further, even if the compatibility can be improved, the silicone oil and the polyurethane resin are not chemically bonded to each other, so that the silicone oil bleeds out with the lapse of time, and there is a problem that the initial purpose cannot be achieved.

In the case where the method of incorporating silicone oil into the main chain by copolymerization of (b), the mechanical strength of the obtained polyurethane resin may be impaired,
Furthermore, in the case of the graft reaction of (c), since the obtained polyurethane resin has only a low-reactivity hydroxyl group in the molecule, it is difficult to chemically modify it and use it for further applications. In addition, there is a problem that the number of reaction steps increases and the production method becomes complicated.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a silicone-modified polyurethane resin which can be used for a new purpose by solving various problems described above and further imparting various preferable characteristics. While studying, polyurethane resin reactant obtained by reacting polydimethylsiloxane of a specific chemical structure with polyisocyanate of a specific chemical structure as an essential component,
It has an isocyanate group in the main chain, and it has been found that the isocyanate group can be used for various preferable applications by using the isocyanate group and that the above problem can be solved, and the present invention has been completed. Therefore, an object of the present invention is to provide a polyurethane resin in a one-step reaction, and to have polydimethylsiloxane and a highly reactive isocyanate group in the main chain of the obtained polyurethane resin. It is an object of the present invention to provide a polyurethane resin reactant which can be variously modified by using a group and can also be self-crosslinked.

[0008]

In order to achieve the above object, the present invention provides (1) (A) a polydimethylsiloxane having an alkyl group at one end and two hydroxyl groups at the other end;
(B) a polyurethane resin reactant obtained by reacting a polyisocyanate having two or more isocyanate groups in a molecule as an essential component, having a polydimethylsiloxane side chain and an isocyanate group in a polyurethane molecular main chain. [2] The polydimethylsiloxane of (A) is represented by the following general formula (1)

[0009]

Embedded image (However, R ¹ is an alkyl group having 1 to 4 carbon atoms; R ² is an ethylene group or a propylene group; R ³ is a hydrogen, a methyl group, or an ethyl group; R ⁴ is a hydroxyl group or a methylhydroxyl group; P is an integer of 0 to 100;
m is an integer of 2 to 9. [3] The polyisocyanate of (B) is a polydimethylsiloxane represented by the following general formula (2):

[0010]

Embedded image (However, Et is an ethyl group; R ⁵ is-(CH ₂ ) ₆ -or

[0011]

Embedded image It is. )).

Further, the present invention provides [4] the following general formula (1):

[0013]

Embedded image (However, R ¹ is an alkyl group having 1 to 4 carbon atoms; R ² is an ethylene group or a propylene group; R ³ is a hydrogen, a methyl group, or an ethyl group; R ⁴ is a hydroxyl group or a methylhydroxyl group; P is an integer of 0 to 100;
m is an integer of 2 to 9. ) And the following general formula (2)

[0014]

Embedded image (However, Et is an ethyl group; R ⁵ is-(CH ₂ ) ₆ -or

[0015]

Embedded image It is. ) With the polyisocyanate represented by
A polyurethane resin reactant characterized by having a polydimethylsiloxane side chain and an isocyanate group in the polyurethane main chain, which are reacted at a molar ratio of 4: 1 to 1:10.

Hereinafter, the present invention will be described in detail.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The chemical structure of a polyurethane resin reactant of the present invention comprises a main chain composed of polyurethane molecules, a polydimethylsiloxane side chain bonded to the main chain, and an isocyanate group bonded to the main chain. This is the main configuration.

The polyurethane resin reactant comprises (A) a polydimethylsiloxane having an alkyl group at one end and two hydroxyl groups at the other end, and (B) two or more isocyanate groups in the molecule. It is produced by reacting with polyisocyanate as an essential component.

Since the polyurethane resin reactant of the present invention thus produced has a highly reactive isocyanate group in the molecule, it can be used for modification with compounds having various functional groups. In addition to the inherent properties of the silicone and polyurethane inherent in the polyurethane resin reactant of the present invention, specific properties can be further added by modification, which can be used for a wider range of applications.

Further, since the polyurethane resin reactant of the present invention can be self-crosslinked alone, it can be suitably used for paints, sealants, adhesives and the like which have been used in the past.

The polydimethylsiloxane having an alkyl group at one end and two hydroxyl groups at the other end of (A) is preferably represented by the following general formula (1).

[0022]

Embedded image In the general formula (1), R ¹ is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, and among them, a butyl group is particularly preferable.

R ² is an ethylene group or a propylene group, particularly preferably an ethylene group.

R ³ is hydrogen, a methyl group or an ethyl group,
Particularly, a hydrogen group is preferable.

R ⁴ is a hydroxyl group or a methyl hydroxyl group, particularly preferably a methyl hydroxyl group.

N is an integer of 0 to 100, p is an integer of 0 to 100, and m is an integer of 2 to 9.

Specific examples of the polydimethylsiloxane (A) include:

[0028]

Embedded image And the like.

As the polyisocyanate having two or more isocyanate groups in the molecule (B), those represented by the following general formula (2) are preferable.

[0030]

Embedded image Here, in the general formula (2), Et represents an ethyl group.

R ⁵ is-(CH ₂ ) ₆ -or

[0032]

Embedded image It is.

In the present invention, the polydimethylsiloxane of the above (A) and the polyisocyanate of the above (B) are reacted to produce a polyurethane resin reactant of the present invention. It is preferable that the isocyanate group of the polyisocyanate of (B) is 1.05 to 15 equivalents to the hydroxyl group of the polydimethylsiloxane of (A).

The polyurethane resin reactant produced by reacting the polydimethylsiloxane of the general formula (1) with the polyisocyanate of the general formula (2) is particularly preferred in the present invention. In this reaction, the polydimethylsiloxane of the general formula (1) and the polyisocyanate of the general formula (2) are preferably reacted in a molar ratio of 1.4: 1 to 1:10. .

If the molar ratio of the polydimethylsiloxane (1) exceeds this, the residual isocyanate groups in the urethane resin reactant will decrease, and the effects and advantages aimed at by the present invention will decrease. In the above reaction, not all the hydroxyl groups and all the isocyanate groups are completely reacted. Therefore, even when the hydroxyl groups are mixed in an excessive amount, the unreacted isocyanate is contained in the urethane molecules to be formed. The group remains.

When the molar ratio of the polyisocyanate (2) exceeds the above range, the unreacted polyisocyanate (2) remains, but in this case, the remaining polyisocyanate has an adverse effect. In the case of 1:
It is preferred to be 3 or less.

In producing the urethane resin reactant of the present invention, it is not necessary to use a special reactor and conditions.

In the above reaction, it is preferable to use a solvent. Examples of the solvent used include esters such as methyl acetate, butyl acetate and ethyl acetate, ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as toluene and xylene, and ethers such as diethyl ether, dibutyl ether, tetrahydrofuran and dioxane. And these can be used alone or as a mixture of two or more.

The use of a catalyst is optional. As the catalyst to be used, known catalysts usually used for the production of urethane resins can be used alone or in combination of two or more. Specific examples include organic tin compounds such as dibutyltin dilaurate and tin dioctoate, and tertiary amines such as triethylamine, N-ethylmorpholine, and 1,8-diazabicyclo (5,4,0) undecene-7.

The amount of the catalyst used is 0.001 to 20% by weight, preferably 0.01 to 20% by weight, based on the urethane resin reactant.
1.0% by weight.

The reaction temperature is preferably from room temperature to 150 ° C., particularly preferably from 50 ° C. to 120 ° C. The reaction time varies depending on whether or not a catalyst is used, but is usually completed in 1 hour to 20 hours.

According to the present invention, a urethane resin reactant is directly synthesized from an isocyanate-containing monomer and an alcohol-modified dimethylsiloxane without using a hydroxyl group-containing resin, and the urethane resin reactant includes a highly reactive isocyanate. And a dimethylsiloxane as a molecular side chain in advance. Further, the polyurethane resin reactant of the present invention can be chemically modified and can be self-crosslinked.

When the polyurethane reactant is further modified by reacting with the isocyanate group, any compound having a functional group which usually reacts with the isocyanate group can be used. Examples of the modifying compound include compounds having an active hydrogen group such as alcohol, carboxylic acid, amine, urea, and urethane.

[0044]

EXAMPLES The present invention will be described more specifically with reference to the following examples.

Example 1 One-terminal diol-modified silicone having a hydroxyl equivalent of 670 represented by the following formula (3): 13.9 g (0.02 as hydroxyl group)
mol)

[0046]

Embedded image 10.0 g (0.03 mol as isocyanate) of a polyisocyanate (Takeda Pharmaceutical Co., Ltd. Takenate D160N) represented by the following formula (4) and having an NCO equivalent of 333.3 and a solid content of 75% by weight:

[0047]

Embedded image And 40 g of toluene in a 100 ml flask,
For 22 hours. FIG. 1 shows a GPC (gel permeation chromatography, eluent toluene) chart when the heating and stirring time is 0 hour and 22 hours. From the chart of FIG. 1, it was confirmed that almost all silicone was consumed after 22 hours and a polymer was obtained.

FIG. 2 shows an IR chart of the reaction composition 22 hours after heating and stirring. From the IR chart, it was confirmed that the reaction composition contained isocyanate and dimethyl silicone. From these analysis results, it was confirmed that the composition obtained by this reaction was a polyurethane resin represented by the following formula (5).

[0049]

Embedded image Embodiment 2. FIG. 13.9 g (0.02 mol as a hydroxyl group) of a hydroxyl-equivalent 670 one-terminal diol-modified silicone represented by the following formula (6):

[0050]

Embedded image Polyisocyanate (Takeda Chemical Industries Takenate D1)
13.3 g (0.04 m as isocyanate)
ol) and 0.2 g of a 1 wt% toluene solution of dibutyltin dilaurate were charged into a 100 ml flask, and heated and stirred at 80 ° C. for 3 hours.

FIG. 3 shows a GPC (eluent toluene) chart when the heating and stirring time is 0 hour and 3 hours.
From the chart of FIG. 3, it was confirmed that almost all of the silicone was consumed.

FIG. 4 shows a 1R chart of the reaction composition after 3 hours of heating and stirring. From the IR chart of FIG. 4, it was confirmed that the obtained composition contained sociocyanate and dimethyl silicone.

Example 3 15.0 g of a diol modified silicone having a hydroxyl equivalent of 2130 at one end represented by the following formula (7) (0.0 as a hydroxyl group)
07 mol),

[0054]

Embedded image Polyisocyanate (Takeda Chemical Industries Takenate D1)
60N) 3.5 g (0.01 mol as isocyanate)
l), 35 g of toluene and 0.2 g of a 1% by weight toluene solution of dibutyltin dilaurate were placed in a 200 ml flask, and heated and stirred at 80 ° C. for 3 hours.

FIG. 5 shows a GPC (eluent toluene) chart when the heating and stirring time is 0 hour and 4 hours. From FIG. 5, it was confirmed that almost all the silicone was consumed at the time of the heating and stirring time of 3 hours. Next, heating and stirring 4
The IR chart of the reaction product after time is shown in FIG. From the IR chart of FIG. 6, it was confirmed that the reaction product obtained after the reaction contained isocyanate.

Curing Test Example 1 The polyurethane resin reactant synthesized in Example 1
It was applied on a glass plate at 5 μm and left at room temperature for 2 days.
After that, when this glass plate was immersed in toluene, a film-like one not dissolved in toluene was observed. This confirmed that self-crosslinking proceeded in the atmosphere.

[0057]

According to the present invention, a urethane resin reactant having a silicone side chain is directly synthesized from an isocyanate-containing monomer and an alcohol-modified dimethylsiloxane. This reaction is completed in one step and is very simple.
Further, since the obtained polyurethane resin reactant chemically bonds silicone as a side chain, it is stable even when used for a long period of time, and silicone does not bleed out. Furthermore, since this polyurethane resin reactant has a highly reactive isosialate group in the molecule, various chemical modifications can be made by using this group, and thus it can be used for various new applications. . In addition, since it has an isocyanate group, it can be self-crosslinked, and therefore can be used for various applications such as paints, binders, adhesives, and sealants, and is extremely useful.

[Brief description of the drawings]

FIG. 1 shows a time-dependent change in the unreacted amount of a diol modified at one end in the synthesis of a polyurethane resin reactant of the present invention in Example 1, and GPC using toluene as an eluent
It is a chart.

FIG. 2 is an IR chart in Example 1 in which a reaction solution after a reaction time of 22 hours is used as an analysis sample.

FIG. 3 shows a time-dependent change in the amount of unreacted diol-modified silicone at one end in the synthesis of the polyurethane resin reactant of the present invention in Example 2, which is GPC using toluene as an eluent.
It is a chart.

FIG. 4 is an IR chart in Example 2 in which a reaction solution after 3 hours of reaction is used as an analysis sample.

FIG. 5 shows a time-dependent change in the amount of unreacted diol-modified silicone at one end in the synthesis of the polyurethane resin reactant of the present invention in Example 3, which is GPC using toluene as an eluent.
It is a chart.

FIG. 6 is an IR chart in Example 3 in which a reaction solution after a reaction time of 4 hours is used as an analysis sample.

Claims (4)

[Claims] 1. (A) a polydimethylsiloxane having an alkyl group on one end side and two hydroxyl groups on the other end side;
(B) a polyurethane resin reactant obtained by reacting a polyisocyanate having two or more isocyanate groups in a molecule as an essential component, having a polydimethylsiloxane side chain and an isocyanate group in a polyurethane molecular main chain. . 2. The polydimethylsiloxane of (A) is represented by the following general formula (1): (However, R ¹ is an alkyl group having 1 to 4 carbon atoms; R ² is an ethylene group or a propylene group; R ³ is a hydrogen, a methyl group, or an ethyl group; R ⁴ is a hydroxyl group or a methylhydroxyl group; P is an integer of 0 to 100;
m is an integer of 2 to 9. The polyurethane resin reactant according to claim 1, which is a polydimethylsiloxane represented by the following formula: 3. The polyisocyanate of (B) has the following general formula (2): (Where Et is an ethyl group; R ⁵ is-(CH ₂ ) ₆ -or It is. The polyurethane resin reactant according to claim 1 or 2, which is a polyisocyanate represented by the following formula: 4. The following general formula (1): (However, R ¹ is an alkyl group having 1 to 4 carbon atoms; R ² is an ethylene group or a propylene group; R ³ is a hydrogen, a methyl group, or an ethyl group; R ⁴ is a hydroxyl group or a methylhydroxyl group; P is an integer of 0 to 100;
m is an integer of 2 to 9. And a polydimethylsiloxane represented by the following general formula (2): (Where Et is an ethyl group; R ⁵ is-(CH ₂ ) ₆ -or It is. ) With the polyisocyanate represented by
A polyurethane resin reactant having a polydimethylsiloxane side chain and an isocyanate group in a polyurethane molecular main chain, which is reacted at a molar ratio of 4: 1 to 1:10.