JPS6215566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid resin composition capable of self-crosslinking and curing.

Recently, a large amount of research is being conducted under the concept of liquid rubber. In short, a relatively low molecular weight liquid polybutadiene compound having reactive functional groups at both ends of the molecular chain is increased in molecular weight and crosslinked using a chain extender or a crosslinking agent to obtain a cured product having rubber-like elasticity. Its main use is in the production of tires etc. using the casting method.

Although many years have passed since the appearance of liquid rubber, it is still at the development stage because it is inconvenient and uncertain to control the chain elongation and crosslinking reactions at the same time, and the crosslinking density may vary. tends to become excessive,
In addition to the fact that it tends to result in hard products with low elongation and low rubber elasticity, in the NCO-terminated prepolymer method that is mainly used, the pot life of the liquid composition is short and the high viscosity makes it difficult to use reinforcing fillers, The main factors hindering development include the poor dispersibility of additives such as curing catalysts, making them difficult to handle.

In order to obtain a crosslinkable cured product from a current liquid rubber composition, the NCO-terminated prepolymer described above is mixed with an amine and cured by heating using a one-shot method, but when an amine is not used, a crosslinking reaction is generally performed. The resulting polymer is susceptible to creep deformation and is easily dissolved in solvents. Various ideas have been made to improve this drawback. One example is the use of polyhydric alcohol as a component of polyester polyol or as a chain extender, but in this case it is equivalent because the number average number of functional groups increases.
The pot life becomes difficult to control due to gelation during synthesis of the NCO-terminated prepolymer or gelation during storage of the prepolymer.

As a result of intensive research, the present inventors found that substantially two terminal isocyanate groups (NCO groups) obtained by reacting an unsaturated polymer diol with an organic diisocyanate having substantially two hydroxyl groups at both ends of the molecule. 0.1 per mole of prepolymer (A) with
Crosslinking with a low viscosity that allows a self-crosslinking cured product to be obtained by coexisting with 1 mol of organic diisocyanate (B) and curing with atmospheric moisture or added moisture in the form of a lump or an inert solvent solution. We have discovered a liquid curable resin composition that allows easy reaction control and long-term stable storage. The curing time and physical properties of the cured product can be adjusted by adding a catalyst and, if necessary, additives such as fillers.The obtained cured product is a tough material that is insoluble in organic solvents, and is Plastic or rubber-like elastic bodies can be produced as desired by selecting the type, molecular weight, etc. of the raw material polymer diol.

That is, the present invention comprises one or more polymer diols or a low molecular weight diol, and at least one diol is α/β-
A composition having unsaturated dicarboxylic acid ester groups, wherein the content of α/β-unsaturated dicarboxylic acid ester groups in the composition is 0.23 or more per hydroxyl group. 0.1 to 1 mole of organic diisocyanate (B) is coexisting per mole of prepolymer (A) having two terminal isocyanate groups obtained by reacting the composition with an organic diisocyanate. The present invention relates to a liquid resin composition that can be crosslinked and cured.

Any of the polymer diols or low molecular weight diols used in the present invention may have an α/β unsaturated dicarboxylic acid ester group, and the α/β unsaturated dicarboxylic acid ester group per hydroxyl group in the composition. It is sufficient if the total number of bases is 0.23 or more. For example, compositions consisting of polymer diols with and without α/β unsaturated dicarboxylic acid ester groups, compositions in which the polymer diol does not have α/β unsaturated dicarboxylic acid ester groups but have low molecular weight diols, etc. There are various cases. If the total is less than 0.3, a self-crosslinking cured product will not be obtained, but a solvent-soluble cured product will be obtained.

The α/β unsaturated dicarboxylic acid ester group is introduced by maleic acid, fumaric acid, itaconic acid, or the like.

The unsaturated diol composition in the present invention is α・
It contains polyester diols such as polyethylene adipate diol containing β-unsaturated dicarboxylate residues, polyether diols, polyolefin diols, low molecular weight diols containing α/β-unsaturated dicarboxylate residues, and the like.

The low molecular weight diol is a diol having 2 to 8 carbon atoms, such as ethylene glycol, 1,4 butanediol, 1,6 hexanediol, neopentyl glycol, 1,3 butylene glycol, trimethylpentanediol and the like. Alternatively, it means a diester of the diol having 2 to 8 carbon atoms and an α/β unsaturated dicarboxylic acid, such as 1,4-butanediol maleate diester, 1,6-hexanediol maleate diester, and the like. These diesters have hydroxyl groups at both ends.

The molecular weight of the polymer diol used in the present invention is at least 500, and 1000 to 3000 is particularly preferable for practical purposes.The reason for this is to obtain a liquid composition with low viscosity. The prepolymer has an extremely high viscosity and becomes very difficult to handle even if diluted with a solvent, but other than this point there is no particular problem, so no upper limit of molecular weight is specified.

The organic diisocyanate has essentially two
Common diisocyanates containing NCO groups are used. In order to make the NCO-terminated prepolymer and the organic diisocyanate coexist, the organic diisocyanate is added after the completion of prepolymerization, or the organic diisocyanate is used in an amount greater than the amount required for prepolymerization during prepolymerization.

The organic diisocyanate is used in an amount of 0.1 to 1 mole per mole of prepolymer. If the amount is less than 0.1 mole, the polymer formed after the composition is cured will become soluble in a solvent such as dimethylformamide. If the amount is too large, the rubber-like elasticity will be lost.

Example 1 Polybutylene adipate maleate diol (molar ratio of adipic acid and maleic acid 83:10) was synthesized by dehydration and esterification (200° C., 8 hours).

This polyester diol has a
Contains 0.23 α/β unsaturated dicarboxylic acid ester groups, hydroxyl value 109.3, acid value 0.7, number average molecular weight
It was 1020.

61.2g (0.06mol) of this polyester diol
and 4,4′ diphenylmethane diisocyanate 33.0
(0.132 mol) is reacted at 100°C for 30 minutes to produce a composition consisting of a prepolymer of isocyanate at both terminals and unreacted 4,4' diphenylmethane diisocyanate.

(The molar ratio of prepolymer and 4,4' diphenylmethane diisocyanate in this composition is 1:0.2.
It is. ) Add 94 g of ethyl acetate to this composition and stir well to obtain a homogeneous solution (solid content 50%) at room temperature.

0.25 g of dibutyltin dilaurate in 50 g of this solution
Pour into a Teflon-coated vat to a depth of about 2 mm, and leave it uncovered at room temperature for 1 day until it hardens due to moisture and has a thickness of about 1 mm.
mm sheets were obtained.

Place this sheet in dimethylformamide,
Although it was left at room temperature for 3 months, it did not dissolve. It does not dissolve even in dimethylacetamide or hexamethylphosphoramide.

When this sheet was tested using a tensile tester, it had the following tensile properties.

Tensile strength 380Kg/ ^cm2 Elongation at break 540% Comparative example 1 Polybutylene adipate (hydroxyl value 113.1 acid value
0.2, number average molecular weight 990) 59.4 g (0.06 mol) and 33.0 g of 4,4' diphenylmethane diisocyanate
(0.132 mol) at 100°C for 30 minutes to create a composition consisting of a prepolymer of a double-ended isocyanate and 4.4' diphenylmethane diisocyanate. The molar ratio is 1:0.2) and 93 g of ethyl acetate is added to make a 50% solution. Dibutyltin dilaurate 0.25 to 50g of this solution
The mixture was poured into a Teflon-coated vat to a depth of about 2 mm, and left uncovered for one day to obtain a film with a thickness of about 1 mm. The sheet was dissolved in dimethylformamide.

The tensile properties of this sheet were as follows: Tensile strength: 350 Kg/cm ² Elongation at break: 550%.

Example 2 61.2g of the same polyester diol as Example 1
(0.06 mol) and hexamethylene diisocyanate
A composition consisting of a prepolymer with terminal isocyanates and hexamethylene diisocyanate prepared by reacting 22.2 g (0.132 mol) at 100°C for 60 minutes (mole ratio of prepolymer and 4,4' diphenylmethane diisocyanate in this composition). 1:0.2) and add 83 g of ethyl acetate to make a 50% solution.

A sheet obtained in the same manner as in Example 1 using this 50% solution did not dissolve in dimethylformamide.

The tensile properties of this sheet were as follows: tensile strength: 230 kg/cm ² elongation at break: 400%.

Example 3 Polyhexylene adipate itaconate diol (mole ratio of adipic acid and itaconic acid 3:1)
was synthesized by dehydration and esterification (200°C for 10 hours).

This polyester diol has a
Contains 0.64 α/β unsaturated dicarboxylic acid ester groups, hydroxyl value 88.8, acid value 0.2, number average molecular weight
It was 1260.

63.0g (0.05mol) of this polyester diol
and 2,4-tolylene diisocyanate 24.4g (0.14
A composition consisting of a prepolymer with terminal isocyanates and 2,4-tolylene diisocyanate prepared by reacting 2,4-tolylene diisocyanate at 100°C for 60 minutes (the molar ratio of the prepolymer and 2,4-tolylene diisocyanate in this composition is 1). : 0.8 mol) to make a 50% solution by adding 87 g of ethyl acetate.

A sheet obtained in the same manner as in Example 1 using this 50% solution did not dissolve in dimethylformamide. The tensile properties of this sheet were as follows: Tensile strength: 440 Kg/cm ² Elongation at break: 500%.

Example 4 Polybutadiene diol (number average molecular weight 1400,
A polymer diol was synthesized by esterification from 2 moles of hydroxyl value 64.9, acid value 0.04, functionality 1.62) and 1 mole of maleic acid. (Number average molecular weight 2960, hydroxyl value 31.0, acid value 0.8) This polymer diol has a molecular weight of 0.5 per hydroxyl group.
It has α/β unsaturated dicarboxylic acid ester groups, and analysis of infrared absorption spectra, nuclear magnetic resonance spectra, etc. confirmed that no addition of ene to the tertiary carbon of polybutadiene occurred. When 118.4 g (0.04 mol) of this polymer diol is reacted with 18.5 g (0.074 mol) of 4,4' diphenylmethane diisocyanate, a composition consisting of the isocyanate prepolymer and unreacted 4,4' diphenylmethane diisocyanate is produced. (The molar ratio of prepolymer to 4.4' diphenylmethane diisocyanate in this composition is 1:0.2). Add 137 g of ethyl acetate to this composition to make a 50% solution.

A sheet obtained in the same manner as in Example 1 using this 50% solution did not dissolve in dimethylformamide.

The tensile properties of this sheet were as follows.

Tensile strength 40Kg/cm ² Elongation at break 150% Comparative example 2 A prepolymer was made from the same polybutadiene diol and 4,4' diphenylmethane diisocyanate used in Example 4, and a sheet obtained in the same manner as in Example 1 was dimethylated. When poured into formamide, there was a very small amount of swollen parts, but most of it dissolved.

Example 5 Polypropylene glycol (number average molecular weight
390) 0.5 α/β per hydroxyl group made by esterification from 2 moles and 1 mole of maleic acid
Polymer diol with unsaturated dicarboxylic acid ester group (number average molecular weight 850) 34.0g (0.04 mol)
and 4,4' diphenylmethane diisocyanate 22.0
4.
A composition consisting of 4' diphenylmethane diisocyanate (in this composition, the molar ratio of prepolymer to 4,4' diphenylmethane diisocyanate is 1:
0.2) and add 56 g of ethyl acetate to make a 50% solution.

A sheet obtained in the same manner as in Example 1 using this 50% solution did not dissolve in dimethylformamide.

The tensile properties of this sheet are as follows.

Tensile strength 110Kg/cm ² Elongation at break 250% Example 6 56.0g (0.04 mol) of the same polybutadiene diol used in Example 4 and 1.
4-butanediol maleic acid diester 15.6g
(0.06 mol) of a composition (the composition contains 0.3 α/β unsaturated dicarboxylic acid ester groups per hydroxyl group) and 25.6 g (0.102 mol) of 4,4' diphenylmethane diisocyanate. When mol) is reacted, a composition consisting of a prepolymer of terminal isocyanate and unreacted 4,4' diphenylmethane diisocyanate is produced. (The molar ratio of prepolymer to 4,4' diphenylmethane diisocyanate in this composition is 1:0.1) 97 g of ethyl acetate is added to this composition to make a 50% solution.

A sheet obtained in the same manner as in Example 1 using this 50% solution did not dissolve in dimethylformamide.

The tensile properties of this sheet were a tensile strength of 70 Kg/cm ² and an elongation at break of 200%.

58.2 g (0.06 mol) of polybutylene adipate malate diol (synthesized by dehydration and esterification of adipic acid and maleic acid in a molar ratio of 96:4 (200°C for 8 hours), hydroxyl value 115.7, number average molecular weight 970) and 4・4'diphenylmethane diisocyanate
When reacting with 33.0g (0.132 mol) at 100℃ for 30 minutes, a prepolymer with isocyanate at both ends and 4.
4' diphenylmethane diisocyanate (the molar ratio of the prepolymer and 4,4' diphenylmethane diisocyanate in this composition is 1:
0.2) is obtained. Add 94 g of ethyl acetate to this composition and stir well to obtain a homogeneous solution (solid content 50%) at room temperature. Add 0.25 g of dibutyltin dilaurate to 50 g of this solution, mix, and pour into a deep Teflon-coated vat. Pour the mixture so that the thickness is approximately 2 mm, and leave it uncovered for a day until the thickness is approximately 1 mm.
A film of mm was obtained. This film was dissolved in dimethylformamide after 10 hours. This sheet had a tensile strength of 360 Kg/cm ² and an elongation at break of 550%.

Claims (1)

[Scope of Claims] 1. A composition comprising one or more polymer diols or a low molecular weight diol and at least one diol having an α/β-unsaturated dicarboxylic acid ester group, , 2 obtained by reacting a composition in which the content of α/β-unsaturated dicarboxylic acid ester groups is 0.23 or more per hydroxyl group with an organic diisocyanate group.
Prepolymer with terminal isocyanate groups
(A) 1 mole of organic diisocyanate (B) 0.1 to 1
1. A liquid resin composition capable of self-crosslinking and curing, characterized in that it contains moles. 2 The polymer diol has a molecular weight of at least 500
Polyester diol or molecular weight of at least
500 or a polybutadiene diol having a molecular weight of at least 500. 3. The liquid resin composition according to claim 1, wherein the low molecular weight diol is a diol having 2 to 8 carbon atoms, or a diester of the diol and an α/β-unsaturated dicarboxylic acid having hydroxyl groups at both terminals. 4. The liquid resin composition according to claim 1, wherein the α/β-unsaturated dicarboxylic acid constituting the α/β-unsaturated dicarboxylic acid ester group is maleic acid, fumaric acid, or itaconic acid. 5. Claim 1, wherein the unsaturated diol having an α/β-unsaturated dicarboxylic acid ester group is polybutylene adipate maleate diol, polyhexylene adipate itaconate diol, or 1,4-butanediol maleic diester The liquid resin composition described in . 6. The liquid resin composition according to claim 1, wherein the unsaturated diol having an α/β-unsaturated dicarboxylic acid ester group is polybutadiene maleate diol or polypropylene maleate diol. 7. The liquid resin composition according to claim 1, wherein the organic diisocyanate is 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, or hexamethylene diisocyanate.