JP2625532B2 - Thixotropic polyurethane resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATION The present invention is used as a coating material, an adhesive or a tooling material. The present invention relates to a polyurethane resin composition, and more particularly, to a thixotropic polyurethane resin composition.

[Conventional technology]

When a polyurethane resin is used as a coating material, an adhesive or a tooling material, it is required to impart thixotropic properties to the resin because it is applied on a vertical surface or a slope.

Numerous proposals have already been made as to a method for imparting thixotropic properties to polyurethane resins.

For example, Japanese Patent Publication No. 45-41110 discloses a thixotropic polyurethane resin comprising a combination of colloidal silica and a polyoxyethylene glycol derivative, and Japanese Patent Publication No. 47-7632 discloses a polyoxyalkylene and an inorganic filler such as colloidal silica. Thixotropic polyurethane resin comprising a combination of compounds, and further Japanese Patent Publication No. 51-11656,52
-1747,53-5899, JP 50-80354, 51-47
046, 60-108479, 60-120750 propose thixotropic polyurethane resin compositions.

However, each of these thixotropic polyurethane resins uses hydrophilic colloidal silica as the main agent of the thixotropic agent.

[Problems to be solved by the invention]

The storage stability of a polyurethane resin in a closed container is an important performance in such a coating material, adhesive or sealing material, and its quality determines the commercial value in the market.

Needless to say, a composition having a high storage stability in a closed container at a temperature relatively higher than ordinary temperature, that is, 50 ° C., and having little change in workability and the like is preferable.

[Means for solving the problem]

It is known that the use of hydrophobic colloidal silica results in better storage stability as compared to hydrophilicity. However, although the use of this type of silica has an effect of increasing the viscosity of the resin composition, thixotropic properties are insufficient.

Therefore, the present inventors have studied compositions to be combined with hydrophobic colloidal silica in order to impart thixotropic properties.As a result, conventional polyoxyethylene derivatives, dimethyl sulfoxide, tetramethyl urea, etc. Polar solvents, etc.
It has been found that a conventionally known combination cannot impart thixotropic properties, and as a result of further intensive studies, it has been found that a bisalkoxysilyl compound is extremely effective in imparting thixotropic properties, and has finally reached the present invention.

That is, the present invention has the following general formula: (Wherein, R represents an oxygen atom or an alkylene bridge having 1 to 15 carbon atoms, and the alkylene bridge may be linear or branched, or may contain a hetero atom.

R ¹ and R ² are CH ₃ or C ₂ H ₅ or _{C m H 2m + 1 OC 2} H 4 or _{C m H 2m + 1 OC 2} H 4 OC 2 H 4, m is 1 to 4, n = 2 or 3 is shown. The present invention relates to a thixotropic polyurethane resin composition comprising a bisalkoxysilyl compound represented by the formula:

That is, the present invention is a thixotropic polyurethane resin composition comprising a polyurethane resin, hydrophobic colloidal silica, and the bisalkoxysilyl compound.

The polyurethane resin as the first component of the present invention is an isocyanate-terminated prepolymer obtained by reacting a polyisocyanate with a known compound having two or more active hydrogens in one molecule under an excess of isocyanate, Or a mixture of the isocyanate-terminated prepolymer and a latent active hydrogen compound.

The polyisocyanates which are constituents of the polyurethane resin of the present invention include: 1) tolylene diisocyanate (including various mixtures of isomers), diphenylmethane diisocyanate (including various mixtures of isomers), 3,3'-dimethyl-4. 4'-
Biphenylene diisocyanate 1,4-phenylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, naphthylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, 1,4- Cyclohexyl diisocyanate, 1
-Methyl-2,4-diisocyanato-cyclohexane,
Diisocyanates such as 2,4,4-trimethyl-1,6-diisocyanato-hexane, etc. 2) tris such as 4,4 ', 4 "-triphenylmethane triisocyanate, tris (4-phenylisocyanato) thiophosphate, etc. 3) Polyfunctional isocyanates such as urethane-modified isocyanates, isocyanurate-modified products, carbodiimidized-modified products, buret-modified products, crude tolylene diisocyanate, and polymethylene polyphenylisocyanate.

The prepolymer having an isocyanate group as a terminal group used in the present invention includes the above-mentioned various organic polyisocyanate compounds and known polyols, known polyamines and the like.
A known compound having two or more active hydrogens in the molecule,
The reaction is carried out by a known method so that free isocyanate groups remain.

That is, it is produced by reacting an isocyanate with a known compound having active hydrogen at 100 ° C. for several hours.

The isocyanate group content is preferably from 0.5 to 10.0% by weight.

As used herein, a known compound having two or more active hydrogens in one molecule refers to two or more hydroxyl groups, one or more amino groups, two or more mercapto groups, A compound having a group and an amino group, or a compound having a hydroxyl group and a mercapto group can be given.

Such compounds include, for example, water, ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, polyhydric alcohols such as sucrose, or aniline, tolylenediamine, p, p'-diaminodiphenylmethane , Such as aromatic amines, ethylenediamine, ethanolamine,
Aliphatic amines or alkanolamines such as diethanolamine and the like, and compounds having two or more active hydrogens in one molecule of these or a mixture of these compounds, and polyether obtained by addition polymerization of propylene oxide or propylene oxide and ethylene oxide -Polyols, polyether-polyamines obtained by converting hydroxyl groups of the polyether-polyols to amino groups, polytetraethylene ether polyols,
Polyester polyols such as polycarbonate polyols, polycaprolactone polyols, polyethylene adipates, polybutadiene polyols, esters of higher fatty acids such as castor oil, polymer polyols obtained by grafting vinyl monomers to polyether polyols or polyester polyols And compounds obtained by copolymerizing known ethylenically unsaturated monomers having one or more active hydrogens in one molecule, and ethers having a mercapto group.

The latent active hydrogen compound used in the polyurethane resin as the first component of the present invention is a compound whose active hydrogen is regenerated by moisture.

The latent active hydrogen compound in which active hydrogen is regenerated by moisture is polyketimine shown in British Patent No. 1064841, or polyenamine shown in Japanese Patent Publication No. 57-16126, Japanese Patent Application No. And β-amino-β-lactams, and compounds such as oxazoline.

The mixing ratio between the isocyanate-terminated prepolymer and the latent active hydrogen compound is the ratio of the number of isocyanate groups to the number of active hydrogen generated by hydrolysis (equivalent ratio).
However, 0.7 to 1.3 is preferable.

Polyurethane resin as the first component of the present invention, viscosity, resin physical properties, fillers to adjust the resistance, plasticizer,
Solvents, adhesion promoters, colorants, and stabilizers can be mixed.

Fillers include, for example, calcium carbonate, talc, kaolin, zeolite, diatomaceous earth, vinyl chloride paste resin,
There are glass balloons, vinylidene chloride resin balloons, etc., which are used in the resin in a range of up to 60% by weight.

Plasticizers include, for example, dioctyl phthalate, dibutyl phthalate, dilauryl phthalate, butyl benzyl phthalate, dioctyl phthalate, diisodecyl adipate, trioctyl phosphate, etc.
Use in the range of weight%.

Solvents include, for example, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, heptane and octane, as well as petroleum solvents ranging from gasoline to kerosene fractions,
There are esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and ether esters such as cellosolve acetate and butyl cellosolve acetate. The resin is used in a range of up to 50% by weight.

A silane coupler or the like is used as an adhesion-imparting agent, a carbon black or titanium white is used as a coloring agent, and a hindered phenol compound, a triazole-based compound or the like is used as a stabilizer.

The second component of the present invention, hydrophobic colloidal silica, is obtained by a combustion hydrolysis method. It is obtained by reacting hydrophilic colloidal silica with dimethyldichlorosilane or trimethylchlorosilane to make the surface hydrophobic.

AEROSIL R972 (DEGUSSA), WACKER HDK H-20
(WACKER) is a typical hydrophobic colloidal silica.

The bisalkoxysilyl compound as the third component of the present invention includes: 1) 1,6-bis (trismethoxyethoxyethoxysilyl) hexane, 1,2-bis (trimethoxysilyl) ethane, bis [3- ( Bisalkoxysilyl compounds such as triethoxysilyl) propyl] tetrasulfide, bis [3- (triethoxysilyl) propyl] amine, 1,3-dimethyltetramethoxydisiloxane, and 2) alkoxysilyl compounds (generally a silane coupling agent) Bisalkoxysilyl compounds obtained by a reaction between each other, for example, 1 mol of isocyanatopropyltriethoxysilane and 1 mol of N-
Compound obtained by reaction with butyl-γ-aminopropyltrismethoxyethoxyethoxysilane, compound obtained by reaction of 1 mol of isocyanatopropyltriethoxysilane with 1 mol of mercaptoethyltriethoxysilane, 1 mol of isocyanatepropyltris Compound obtained by reacting methoxyethoxysilane with 1 mol of hydroxyethyltriethoxysilane, 1 mol of γ
A compound obtained by reacting 1-mol of γ-glycidoxypropyltrismethoxyethoxysilane with 1 mol of aminopropyltrismethoxyethoxysilane, 3) a compound obtained by reacting 2 mol of a monosilane compound having active hydrogen and 1 mol of diisocyanate For example, compounds obtained by the reaction of γ-aminopropyltrismethoxyethoxyethoxysilane with isophorone diisocyanate, mercaptoethyltriethoxysilane with diphenylmethane diisocyanate, and hydroxyethyltriethoxysilane with xylylene diisocyanate.

The mixing ratio of the composition of the present invention is 100% of polyurethane resin.
The hydrophobic colloidal silica is particularly preferably 0.5 to 50 parts by weight, and the bisalkoxysilyl compound is particularly preferably 0.1 to 30 parts by weight with respect to parts by weight.

In the present invention, the hydrophobic colloidal silica, and a polyurethane resin composition containing the bisalkoxysilyl compound has high storage stability, even at a relatively high temperature,
A resin with little change in workability can be obtained.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

 The middle part in the examples indicates parts by weight.

 The following materials were used in the examples.

Isocyanate-terminated prepolymer: Prepolymer A: 2,4 as a diisocyanate
Using 598 parts of tolylene diisocyanate, 2600 parts of polyoxypropylene glycol (molecular weight 2000), 1802 parts of polyoxypropylene triol (molecular weight 3000),
The reaction was carried out at 0 ° C. for 10 hours to obtain a prepolymer A.

The terminal NCO group was 1.89% and the viscosity was 41,000 cps / 25 ° C.

Prepolymer B: Using 973 parts of isophorone diisocyanate as the diisocyanate, 5081 parts of polyoxypropylene glycol (molecular weight 3000), 3946 parts of polyoxypropylene triol (molecular weight 5000), and 0.5 part of catalyst dibutyltin dilaurate as 100 parts The mixture was reacted at a temperature of 3 ° C. for 3 hours to obtain a prepolymer B.

The terminal NCO group was 1.12%, and the viscosity was 48,000 cps / 25 ° C.

Prepolymer C: di-isocyanate, p,
Using 218 parts of p'-diphenylmethane diisocyanate, polyoxypropylene glycol (molecular weight 3000)
85 parts, polyoxypropylene triol (molecular weight 4000)
397 parts, catalyst dibutyltin dilaurate 0.02 parts, 100 ℃
For 5 hours, and then 200 parts of xylene was charged while cooling with air to obtain a prepolymer C.

The terminal NCO group was 1.31%, and the viscosity was 17,200 cps / 25 ° C.

Hydrophobic colloidal silica: WACKER HDK H-20 Latent active hydrogen compound: enamine ........... Enamine (ENA) obtained by condensing secondary amine with aldehyde or ketone Here, examples of combinations suitable for the present invention are as follows.

That is, ENA-1 is obtained by condensing 1 mol of dimer tall oil fatty acid with 2 mol of anhydrous piperazine, and further condensing 1 mol of the obtained secondary diamine with 2 mol of 3,3,5-trimethylcyclohexanone. Is enamine.

β-amino-β-lactam: An organic isocyanate is added to a condensate of a secondary amine and an aldehyde to produce β-amino-β-lactam (LAC). An example is as follows.

That is, LAC-1 is obtained by condensing 2 mol of isobutyraldehyde with 1 mol of 4,4'-dipiperidylpropane,
It is a lactam obtained by adding 2 mol of tolyl isocyanate.

Bisalkoxysilyl compound: Bisalkoxysilyl compound A: 245 parts of isocyanatopropyltriethoxysilane, N-butyl-γ-
Aminopropyl trismethoxyethoxyethoxysilane
499 parts were added dropwise with stirring, and after completion of the addition, the mixture was reacted at 60 ° C. for 1 hour to obtain bisalkoxysilyl compound A (BSA).
I got

Bisalkoxysilyl compound B: 443 parts of γ-aminopropyltrismethoxyethoxyethoxysilane was added dropwise to 112 parts of isophorone diisocyanate with stirring, and after the completion of the addition, the mixture was reacted at 60 ° C. for 1 hour to obtain a bisalkoxysilyl compound B ( BSB).

Bisalkoxysilyl compound C: 87 parts of tolylene diisocyanate, hydroxyethyltriethoxysilane
208 parts were added dropwise with stirring, and after completion of the addition, the mixture was reacted at 80 ° C. for 5 hours to obtain a bisalkoxysilyl compound C (BSC).
I got

Thixotropic properties were evaluated by the slump test specified in 6.2 of JIS-A5758 (1986).

Changes in storage stability and workability were evaluated as a one-pack moisture-curable polyurethane resin composition, and after tightly storing for a certain period of time, JIS-K2808 (1961) gave a 2 second value and a 5 second value of penetration [ 10 ^-1 mm].

The physical properties of the cured urethane resin composition were measured according to JIS-K6301.

As the curing condition, a condition was employed in which the film was left at 23 ° C. and a relative humidity of 50% for 7 days, and further left at 50 ° C. for 7 days.

Example 1 In a 3 liter planetary mixer, 370 parts of dioctyl phthalate, 500 parts of calcium carbonate, and 100 parts of titanium oxide were added.
Parts, 10 parts of weather stabilizer (Irganox 1010)
The mixture was kneaded at room temperature for 15 minutes, and then dewatering operation was performed in vacuum for 1 hour while kneading at 100 ° C.

Next, bis [3- (triethoxysilyl) propyl]
10 parts of tetrasulfide (BTS), 582 parts of prepolymer A,
128 parts of a 60% cellosolve acetate solution of β-amino-β lactam LAC-1 was charged and kneaded at room temperature for 15 minutes.

Further, 120 parts of colloidal silica WACKER HDKH-20,
180 parts of xylene was charged and kneaded in a vacuum at room temperature for 10 minutes to obtain a one-component curable polyurethane resin of the present invention.

As shown in Table 2, the urethane resin composition had no slump and good thixotropic properties as compared with the composition using hydrophilic silica.

Further, the storage stability after closed storage at 50 ° C. for 14 days was remarkably improved, and the physical properties of the cured resin were excellent.

Example 2 In a 3 liter planetary mixer, 370 parts of dioctyl phthalate, 500 parts of calcium carbonate, and 100 parts of titanium oxide were added.
Parts, 10 parts of weather stabilizer (Irganox 1010)
The mixture was kneaded at room temperature for 15 minutes, and then dewatering operation was performed in vacuum for 1 hour while kneading at 100 ° C.

Next, 10 parts of a bisalkoxysilyl compound A, 603 parts of a prepolymer B, and 107 parts of a 80% dioctyl phthalate solution of enamine ENA-1 were charged and kneaded at room temperature for 15 minutes.

Further, 120 parts of colloidal silica WACKER HDKH-20,
180 parts of xylene was charged and kneaded in a vacuum at room temperature for 10 minutes to obtain a one-component curable polyurethane resin of the present invention.

As shown in Table 2, the urethane resin composition had no slump and good thixotropic properties as compared with the composition using hydrophilic silica.

Further, the storage stability after sealed storage at 50 ° C. for 14 days was remarkably improved, and the physical properties of the cured resin were excellent.

Example 3 In a 3 liter planetary mixer, 370 parts of dioctyl phthalate, 500 parts of calcium carbonate, and 100 parts of titanium oxide were added.
Parts, 10 parts of weather stabilizer (Irganox 1010)
The mixture was kneaded at room temperature for 15 minutes, and then dewatering operation was performed in vacuum for 1 hour while kneading at 100 ° C.

Next, 10 parts of the bisalkoxysilyl compound B and 710 parts of the prepolymer C were charged and kneaded at room temperature for 15 minutes.

Further, 120 parts of colloidal silica WACKER HDKH-20,
180 parts of xylene was charged and kneaded in a vacuum at room temperature for 10 minutes to obtain a one-component moisture-curable polyurethane resin of the present invention.

As shown in Table 2, the urethane resin composition had no slump and good thixotropic properties as compared with the composition using hydrophilic silica.

Further, the storage stability after closed storage at 50 ° C. for 14 days was remarkably improved, and the physical properties of the cured resin were excellent.

Example 4 A one-part hardened polyurethane resin was obtained in the same manner as in Example 2 except that 10 parts of bisalkoxysilyl compound C (BSC) was used instead of bisalkoxysilyl compound A.

Example 5 A one-part curable polyurethane resin was prepared in the same manner as in Example 3, except that 10 parts of 1,3-dimethyltetramethoxydisiloxane (DTS) was used instead of the bisalkoxysilyl compound B. I got

Comparative Example 1 A one-part curable polyurethane resin was obtained in the same manner as in Example 1, except that hydrophilic colloidal silica AEROSIL # 200120 parts was used as the colloidal silica.

As shown in Table 2, this urethane resin composition has a thickness of 50%.
At 14 ° C., storage stability after closed storage for 14 days resulted in significantly poorer results.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C09K 3/10 C09K 3/10 D

Claims (1)

(57) [Claims] (1) polyurethane resin, (2) hydrophobic colloidal silica, and (3) the following general formula: (However, R represents an oxygen atom or an alkylene bridge having 1 to 15 carbon atoms, and the alkylene bridge may be linear or branched, or may contain a hetero atom. R ¹ and R ² represents CH ₃ or C ₂ H ₅ or C _m H _2m + ₁ OC ₂ H ₄ or C _m H _2m + ₁ OC ₂ H ₄ OC ₂ H ₄ , m represents 1-4, n = 2 or 3 A thixotropic polyurethane resin composition comprising a bisalkoxysilyl compound represented by the formula: