JP2003138128A - Polyurethane paste composition and sealing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both a polyurethane paste composition having stability with time and giving a cured product a improved in mechanical strength of, and to provide a sealing material. SOLUTION: This polyurethane paste composition comprises fine particles (A) composed of a polyurethane resin (a), a plasticizer (B) and a filler (C). In the paste composition, the plasticizer (B) is composed of an aromatic monocarboxylic acid ester (B1). The sealing material comprises the composition. The cured material is prepared by heat curing of the composition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyurethane paste composition mainly applied to vehicles. More specifically, the present invention relates to a polyurethane paste composition having excellent viscosity stability over time in a paste state and good physical properties such as mechanical strength after heat solidification (swelling integration).

[0002]

2. Description of the Related Art Conventionally, for example, in a steel plate joint portion or a steel plate edge portion of an automobile body after electrodeposition coating, in order to watertightly and airtighten those portions and to improve rust prevention property, prior to finish coating. The sealing composition is applied and coated. Further, an undercoat composition is applied to the lower floor of a vehicle body, a wheel house, a side sill, etc. in order to improve rust prevention and chipping resistance.

These sealing or undercoating compositions are vinyl chloride resins, vinylidene chloride resins, etc. because of their excellent rust resistance, ability to form thick films, and low cost. A so-called vinyl chloride-based plastisol composition has been widely used in which the crystalline resin powder (1) is plasticized with a phthalic acid-based plasticizer, and an appropriate filler and other additives are added to the plasticized resin powder. However, this material has a problem in terms of environmental safety, and as a material with higher environmental safety, fine particles made of polyurethane resin,
A polyurethane paste composition (Japanese Unexamined Patent Publication No. 2000-345027) has been proposed which comprises a plasticizer composed of a phosphoric acid ester or a phthalic acid ester, and a filler.

[0004]

However, when the paste composition of the present invention is stored for a long period of time, there is a problem that the plasticizer permeates the fine particles over time and the paste composition thickens. If a plasticizer having a low permeability to fine particles is used to solve this problem, the mechanical strength of the solidified product is not sufficiently exhibited.
That is, the problem to be solved by the present invention is to achieve both the stability over time of the paste composition and the improvement of the mechanical strength of the solidified product.

[0005]

The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems. That is, the present invention provides a paste composition comprising fine particles (A) comprising a polyurethane resin (a), a plasticizer (B) and a filler (C), wherein the plasticizer comprises an aromatic monocarboxylic acid monoester (B1). A polyurethane paste composition comprising: a sealing material comprising the composition; a solidified product obtained by solidifying the composition by heating; and an automobile body coated with the sealing material. The present invention will be described in detail below.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polyurethane resin (a) in the present invention is not particularly limited and can be obtained by a known method. For example, an excess diisocyanate (a1) and a high molecular diol having a number average molecular weight of 500 to 10,000 are used. (A2)
And an isocyanate group-terminated urethane prepolymer (a
0), an aliphatic diamine (b1), and a monoamine (b2) having 1 or 2 alkanol groups having 2 to 4 carbon atoms or an aliphatic monoamine (b3).

The above diisocyanate (a1) includes
For example, carbon number (excluding carbon in NCO group, the same applies hereinafter) 2-1
8 aliphatic diisocyanates [ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-
Diisocyanatohexanoate, etc.]; C4-C15 alicyclic diisocyanate [isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate ( Hydrogenated TDI), bis (2-isocyanatoethyl) -4-cyclohexene, etc.]; Aromatic diisocyanate having 6 to 14 carbon atoms [1,3-
And / or 1,4-phenylene diisocyanate,
2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4′- and / or 4,4′-diphenylmethane diisocyanate (MD
I), 4,4'-diisocyanatobiphenyl, 3,3 '
-Dimethyl-4,4'-diisocyanatobiphenyl,
3,3'-Dimethyl-4,4'-diisocyanatodiphenylmethane, crude MDI, 1,5-naphthylene diisocyanate, etc.]; Aroaliphatic diisocyanate having 8 to 15 carbon atoms [m-
And / or p-xylylene diisocyanate (XD
I), α, α, α ', α'-tetramethylxylylene diisocyanate (TMXDI), etc.]; modified products of these diisocyanates (modified diisocyanates having carbodiimide group, uretdione group, uretoimine group, urea group, etc.); And a mixture of two or more of these. Of these, preferred are alicyclic diisocyanates, aromatic diisocyanates and araliphatic diisocyanates, and particularly preferred are IPDI, hydrogenated MDI, MDI, XDI and TMXDI.

As the polymer diol (a2), polyester diol (a21), polyether diol (a22), polyether ester diol (a23)
And a mixture (a24) of two or more of these.

As the polyester diol (a21), for example, (a211) low molecular diol is a polycarboxylic acid or its ester-forming derivative [acid anhydride, lower alkyl (C1-4) ester, acid halide, etc.] (A212) a ring-opening polymerization of a lactone monomer using a low molecular weight diol as an initiator; and (a213) a mixture of two or more thereof.

Specific examples of the low molecular weight diol in (a211) include aliphatic diols [linear diols (ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol). , 1,6-hexanediol, etc., a diol having a branched chain (propylene glycol, neopentyl glycol, 3-methyl 1,5-pentanediol, 2,2-diethyl-1,3-propanediol,
1,2-, 1,3- or 2,3-butanediol etc.); diols having a cyclic group [for example, those described in JP-B-45-1474; 1,4-bis (hydroxymethyl) cyclohexane] , M- or p-xylylene glycol, ethylene oxide (hereinafter abbreviated as EO) or propylene oxide (hereinafter abbreviated as PO) adduct of bisphenol A (molecular weight less than 500), etc.]
And mixtures of two or more thereof. Among these, preferred is EO or P of bisphenol A.
It is an O adduct.

Specific examples of the polycarboxylic acid or its ester-forming derivative in (a211) include aliphatic polycarboxylic acids having 4 to 15 carbon atoms [succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid. Acid, fumaric acid, etc.], aromatic polycarboxylic acid having 8 to 12 carbon atoms [terephthalic acid, isophthalic acid, etc.], ester-forming derivatives thereof [acid anhydride, lower alkyl ester (dimethyl ester, diethyl ester, etc.), Acid halide (such as acid chloride)] and mixtures of two or more thereof.

As the lactone monomer in (a212), γ-butyrolactone, ε-caprolactone, γ-
Barrel lactones and mixtures of two or more thereof.

Examples of the polyether diol (a22) include compounds having a structure in which an alkylene oxide (hereinafter abbreviated as AO) is added to two hydroxyl group-containing compounds (for example, the aforementioned low molecular diol, divalent phenols, etc.). .

Examples of the divalent phenols include bisphenols [bisphenol A, bisphenol F, bisphenol S, etc.], monocyclic phenols [catechol, hydroquinone, etc.] and the like.

As AO, EO, PO, 1,2-,
1,3-, 1,4- or 2,3-butylene oxide, styrene oxide, α-olefin oxide having 5 to 10 or more carbon atoms, epichlorohydrin and a mixture of two or more thereof (block or random addition) can be used. Can be mentioned.

Of these, preferred are low molecular diols to which AO is added, and more preferred are aliphatic diols to which PO is added.

Further, (a23) is obtained by polycondensing one or more of the above polyether diols and one or more of the polycarboxylic acids or the ester-forming derivatives thereof exemplified as the raw material of the above polyester diol. There are things.

Among (a2), the preferred one is (a2
1), more preferred is a condensed polyester diol derived from an AO adduct of bisphenol A and one or more polycarboxylic acids, and particularly preferred is derived from an AO adduct of bisphenol A and terephthalic acid. Polyester diol.

The number average molecular weight of (a2) is preferably 500 to 10,000, from the viewpoint of elongation and strength of the solidified product.
It is more preferably 600 to 5,000, further preferably 1,000 to 3,000.

As (a3), the compounds exemplified as the starting materials for the polyester diol can be used. Of these (a3), preferred is an aliphatic diol.

(A1) and (a) when forming (a0)
The equivalent ratio of 2) and (a3) is such that (a2) is usually 0.1 to 0.6 equivalents, preferably 0.2 to 0.5 equivalents, and (a3) is usually 0 relative to 1 equivalent of (a1). ~ 0.2 equivalents,
It is preferably 0.05 to 0.10 equivalent. Further, the isocyanate group content of the urethane prepolymer (a0) is usually 0.5 to 10% by weight, preferably 1.5 to 6% by weight.
Is.

The polyurethane resin (a) is the above-mentioned isocyanate group-terminated urethane prepolymer (a0), aliphatic diamine (b1), and monoamine (b2) having one or two hydroxyalkyl groups having 2 to 4 carbon atoms. Alternatively, it can be obtained by reacting an aliphatic monoamine (b3).

The above (b1) includes alicyclic diamine [4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, isophoronediamine, etc.]; aliphatic diamine [ethylenediamine, hexamethylenediamine, etc.] And araliphatic diamines [xylylenediamine, α, α, α ′, α′-tetramethylxylylenediamine, etc.] and mixtures of two or more thereof. Of these, preferred are alicyclic diamines and aliphatic diamines, and particularly preferred are isophoronediamine and hexamethylenediamine.

Examples of (b2) include monoalkanolamine [monoethanolamine, monopropanolamine, etc.]; dialkanolamine [diethanolamine,
Dipropanolamine and the like] and mixtures of two or more thereof. Among these, preferred are dialkanolamines, and particularly preferred are diethanolamine and dipropanolamine.

As the above (b3), alicyclic monoamine
[Cyclopentylamine, cyclohexylamine, etc.], aliphatic monoamines [methylamine, ethylamine, propylamine, butylamine, octylamine, 2-ethylhexylamine, nonylamine, oleylamine, N-
Methylbutylamine, diethylamine, dibutylamine, etc.] and mixtures of two or more thereof. Of these, preferred are aliphatic monoamines, and particularly preferred are butylamine, octylamine, 2-
Ethylhexylamine and dibutylamine.

The equivalent ratio of (b1) to 1 equivalent of isocyanate groups of the urethane prepolymer (a0) is usually 0.
2 to 0.98 equivalent, preferably 0.5 to 0.95 equivalent, and the equivalent ratio of (b2) or (b3) is usually 0.02 to 0.2 equivalent, preferably 0.05 to 0.15
It is equivalent. The polyurethane resin of the present invention contains a urea bond, and the ratio of the urea bond to the urethane bond in the resin is 9/1.
It is preferably ˜1 / 10.

The particle shape of the fine particles (A) of the present invention may be amorphous or spherical, but spherical particles are preferable in view of fluidity of the paste at room temperature and solidification during heating and solidification. Fifty
% Or more is preferable. Here, the term "spherical" refers to particles having a ratio of major axis / minor axis of particles in the range of 1.0 to 1.5.

The average particle diameter of the fine particles (A) of the present invention is preferably 0. 0 from the viewpoint of storage stability and solidification of the paste.
The thickness is 1 to 200 μm, more preferably 1 to 100 μm, and particularly preferably 1 to 50 μm.

The method for producing the above-mentioned fine particles (A) is not particularly limited, but the following method can be exemplified. A method of obtaining a powder (A) by pulverizing a block-shaped or pellet-shaped polyurethane resin by a method such as a freeze pulverization method or an ice pulverization method. A non-aqueous dispersion of the polyurethane resin is formed in an organic solvent that does not dissolve the polyurethane resin (n-hexane, cyclohexane, n-heptane, etc.), and the non-aqueous dispersion is solid-liquid separated and dried to obtain the powder (A). Method (for example, JP-A-04-04)
-255755 gazette specification method). A method of forming an aqueous dispersion of a polyurethane resin in water containing a dispersant, and solid-liquid separating and drying the aqueous dispersion to obtain a powder (A) (for example, JP-A-07-133423 and JP-A-08- No. 120041, the method described in each publication). Of these, the method is preferable in that a powder having a desired shape and particle diameter can be easily obtained without using a large amount of organic solvent.

In the method (1), unlike the prepolymer method described above, the polyisocyanate (a1) and the high molecular diol (a2) and, if necessary, the low molecular diol (a) are used.
A polyurethane resin obtained by reacting (3) together (one-shot method) can be used. Specifically, the method of (A) is performed by dispersing the urethane resin or the urethane resin solution in an organic solvent that does not dissolve the polyurethane resin such as cyclohexane with stirring, and taking out the fine particles dispersed in the solvent and drying (A). Is a way to get. Specifically, the method of (2) can obtain fine particles of a polyurethane resin by reacting the isocyanate group-terminated urethane prepolymer (a0) with an elongation agent and optionally a terminating agent and a crosslinking agent in an aqueous medium. Examples of the extender include aliphatic diamines (b1) and blocked products of (b1). Preferably (b
It is a block product of 1). Examples of the blocking agent include ketones having 3 to 8 carbon atoms (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Examples of the terminating agent include monoamines (b2) having one or two alkanol groups having 2 to 4 carbon atoms and aliphatic monoamines (b3). Examples of the crosslinking agent include polyamines having a valence of 3 to 6 (diethylenetriamine, triethylenetetramine). Urethane prepolymer (a
The equivalent ratio of the extender to 1 equivalent of the isocyanate group of 0) is usually 0.2 to 0.98 equivalent, preferably 0.5 to
0.95 equivalent, and the equivalent ratio of the terminator is usually 0.
To 0.2 equivalent, preferably 0.05 to 0.15 equivalent, and the equivalent ratio of the crosslinking agent is usually 0 to 0.05 equivalent, preferably 0 to 0.02 equivalent.

The number average molecular weight of the polyurethane resin (a) is usually 1,000 to 2 from the viewpoint of melt viscosity during solidification.
0,000, preferably 10,000 to 100,000
It is 0.

The thermal softening point of (a) is usually 80 to 250 ° C., preferably 100 to 200 ° C., and more preferably 140 to 180 from the viewpoint of storage stability and solidification property of the paste.
℃. The thermal softening point here can be measured by a thermomechanical analysis penetration method (measurement conditions: temperature rising rate 5 ° C./min, load 5 g, needle diameter 0.5 mm). This thermomechanical analysis introductory method is described, for example, by Yasutoshi Saito, "Basics of Thermal Analysis for Material Science" [published by Kyoritsu Publishing in 1990], page 350, and edited by The Japan Society for Thermometry "Basics and Applications of New Thermal Analysis" [ (stock)
Realize Co., Ltd.] The method described on page 68.

The glass transition temperature (Tg) of (a) is usually -100 ° C to 200 ° C, preferably -30 ° C to 150.
C., more preferably 30 to 120.degree. Note that Tg here is a differential scanning calorimeter (RTC22 manufactured by Seiko
The temperature can be measured by raising and lowering the temperature between 0 and -50 to 250 ° C. and measuring the heat absorption and heat generation at that time.

The solubility parameter of (a) (hereinafter abbreviated as SP value) is usually 8 to 13, and preferably 9 to 12.
The SP value referred to here is "Poymer Eng."
inering and Science, Vol.
14, No. 2, p147-154 (1974) ”.

The plasticizer (B) used in the present invention comprises an aromatic monocarboxylic acid monoester (B1). (B
1) includes an ester of an aromatic monocarboxylic acid and a monohydric alcohol, or an AO adduct of a monohydric alcohol or a monohydric phenol. As the aromatic monocarboxylic acid, benzoic acid which may be substituted with an alkyl group having 1 to 8 carbon atoms and / or a halogen and / or an alkoxy group,
Examples include cinnamic acid and naphthoic acid. Examples of the monohydric alcohol include alkanols having 1 to 30 carbon atoms, alkenols, cycloalkanols, and arylalkanols. Examples of the monohydric phenol include phenol, alkyl (having 1 to 10 carbon atoms) phenol, benzylated or / and styrenated phenol, and naphthol. Examples of AO include AO having 1 to 4 carbon atoms, for example, ethylene oxide, propylene oxide, tetrahydrofuran, and a combination (random and / or block) of two or more thereof. The number of moles of AO added is usually 1 to 30, preferably 1 to 15. Among (B1), from the viewpoint of compatibility between the plasticizer and the urethane resin and the mechanical strength of the paste solidified product, and from the viewpoint of the time for the plasticizer to be compatible with the urethane resin during solidification, the following general formula What is represented by (1) is preferable. Q-COO- (A
O) n-R (1) [R has 1 to 2 carbon atoms
An alkyl group of 0 or an alkylaryl group of 7 to 26 carbon atoms, A is an alkylene group of 2 to 4 carbon atoms, n is an integer of 1 to 30, and Q is a carbon number of 6 to 14 and a carbon number of 1 to 8 It is a phenyl group which may be substituted with an alkyl group and / or a halogen and / or an alkoxy group. ]

Specifically, as Q, phenyl group, 2- and 4-methylphenyl group, 2-chlorophenyl group, 4
-Ethoxyphenyl group and the like are mentioned, and among these, a phenyl group is preferable. Examples of A include an ethylene group, a 1-methylethylene group, and a 1,4-butylene group, and among these, an ethylene group is preferable. Examples of R include alkyl groups such as octyl group and dodecyl group, and alkylaryl groups such as butylphenyl group, octylphenyl group, dodecylphenyl group and octadecyl group. Among them, octylphenyl group and dodecylphenyl group are included. preferable. From the above, as a preferable example of (B1), C4 to
Examples thereof include a benzoic acid ester of an ethylene oxide adduct of alkylphenol having a C18 alkyl group (addition mole number 4 to 20).

From the viewpoint of fluidity at low temperatures, the melting point of (B1) is preferably 0 ° C. or lower, more preferably −30.
It is -50 ° C or lower. The melting point referred to here is a differential scanning calorimeter (RTC220, -10 manufactured by Seiko Ltd.).
The temperature can be measured by increasing and decreasing the temperature between 0 and 100 ° C. and measuring the endotherm and heat generation at that time.

In the polyurethane paste composition of the present invention, as (B), a plasticizer other than (B1) may be used in combination. Examples of the plasticizer that can be used in combination include plasticizers such as phthalic acid ester, phosphoric acid ester, sebacic acid ester, epoxidized ester, and polyester.

In the present invention, as the filler (C),
Inorganic powder (heavy calcium carbonate, heavy calcium carbonate,
Kaolin, talc, mica, bentonite, clay, sericite, asbestos, metal powder, ceramic powder, zeolite, slate powder, glass powder), balloons (glass balloon, ceramic balloon, silas balloon,), resin powder (acrylic resin powder) , Phenol resin powder, epoxy resin powder, asphalt powder, coal powder), inorganic fibers (glass fiber, carbon fiber), organic fibers (aramid fiber, nylon fiber, acrylic fiber).

In the polyurethane paste composition of the present invention, the blending ratio of (B) and (C) to (A) is 50 to 300 (B) per 100 parts by weight of (A).
Parts by weight, more preferably 50 to 200 parts by weight, (B1) is preferably 40 to 250 parts by weight,
It is more preferably 50 to 200 parts by weight, (C) is preferably 1 to 300 parts by weight, and more preferably 50 to 200 parts by weight.
It is 200 parts by weight.

In the paste composition of the present invention, a blocked polyisocyanate (D) may be added, if necessary, for the purpose of improving the resin strength after solidification. The (D) comprises a polyisocyanate (d1) and a blocking agent (d2). Examples of the above (d1) include the polyisocyanates exemplified in the above (a1) and modified products thereof (for example, isocyanurate group, buret group,
At least one polyisocyanate selected from modified products having a carbodiimide group and the like can be mentioned. The number of isocyanate groups in (d1) is usually 2 or more, preferably 3 to 4. Preferred as (d1) is an isocyanurate modified product of isophorone diisocyanate,
It is an isocyanurate modified product of hexamethylene diisocyanate and a buret modified product of hexamethylene diisocyanate.

Examples of the above (d2) include oximes [acetoxime, methylisobutylketoxime, diethylketoxime, cyclopentanone oxime, cyclohexanone oxime, methylethylketoxime, etc.]; lactams [γ-butyrolactam, ε-caprolactam, γ
Valerolactam and the like]; aliphatic alcohols having 1 to 20 carbon atoms [ethanol, methanol, octanol and the like];
Phenols [phenol, m-cresol, xylenol, nonylphenol, etc.]; active methylene compounds [acetylacetone, ethyl malonate, ethyl acetoacetate, etc.]; basic nitrogen-containing compounds [N, N-diethylhydroxylamine, 2-hydroxypyridine, Pyridine N
-Oxide, 2-mercaptopyridine, etc.]; and a mixture of two or more thereof. Of these, preferred are oximes, and particularly preferred is methyl ethyl ketoxime.

In the paste composition of the present invention, (A)
The ratio of (D) to (A) is usually 0 to 20 parts by weight, preferably 5 to 15 parts by weight per 100 parts by weight of (A).
Parts by weight.

In the paste composition of the present invention, the pigment (E) can be added if necessary. Above (E)
Is not particularly limited, and known organic pigments and / or inorganic pigments can be used. Examples of organic pigments include insoluble azo pigments, soluble azo pigments, copper phthalocyanine pigments, and quinacridone pigments, and examples of inorganic pigments include chromates, ferrocyanine compounds, metal oxides, selenium sulfide compounds, metal salts. (Sulfates, silicates, carbonates, phosphates, etc.), carbon black and the like.

In the paste composition of the present invention, (A)
The mixing ratio of (E) to (A) is usually 0 to 5 parts by weight, preferably 1 to 3 parts by weight, per 100 parts by weight of (A).

The method for producing the polyurethane paste composition of the present invention is not particularly limited, but the following method is exemplified. A method in which the powder of (A), (B) and (C) are mixed together by a mixing device. A method in which (A) and (B) are mixed in advance and this is mixed with the powder of (C). A method of preliminarily containing a part or all of (B) and (C) at an arbitrary stage of producing the powder of (A).

The apparatus for producing the composition of the present invention is not particularly limited, and a known mixing / dispersing apparatus can be used. As the mixing device, a high speed shear mixing device (for example, Henschel mixer, etc.), a low speed mixing device (for example, Nauta mixer,
Planetary mixers, etc.), bead mills, three rolls, etc. If necessary, an anionic, cationic or nonionic dispersant can be used.

When the paste composition of the present invention is applied to a desired portion and then heated at a temperature of 100 to 180 ° C., the resin fine particles absorb the plasticizer and swell, and become integrated with the filler to form a solidified product. The Tg of the solidified product is preferably −70 ° C. to 10 ° C., more preferably −70 ° C. to −30 ° C., from the viewpoint of preventing breakage of the solidified product at low temperatures.

The sealing material comprising the paste composition of the present invention is used for sealing automobile bodies, machine parts and the like. Normally, it is used as a sol-like product having desired fluidity at room temperature, but in applications where dripping during heating is a problem, such as for mohawk parts of automobiles, a shape-retaining agent is used together or a paste composition is used. Supports things (nonwoven fabric, paper,
It can be used after being impregnated into a fiber, a film or the like) and processed into a roll shape, a tape shape or a sheet shape.

The composition of the present invention has a viscosity at 25 ° C. of 5,
It is preferably 000 cP to 300,000 cP. From the viewpoint of preventing sagging during coating, 5,000 cP or more is preferable, and from the viewpoint of enabling discharge from the coating machine, 300,
It is preferably 000 cP or less. The viscosity of the composition can be measured with a BH type viscometer.

In the composition of the present invention, as a morphological agent,
A thermoplastic resin (F) and / or a crystalline compound (G) that is solid at room temperature and that quickly softens when heated to 80 ° C. or more can be added. (F)
The composition containing (G) and / or (G) preferably has a hardness (JIS A) at 25 ° C. of 20 or more from the viewpoint of shape retention, and preferably 80 or less from the viewpoint of workability. The hardness can be measured according to JIS K6301.

(F) is not particularly limited as long as it can be mixed and dispersed in other materials to be used, and examples thereof include addition polymerization type, polycondensation type, polyaddition type and ring opening polymerization type resins. .

As the addition polymerization type resin, polyethylene,
Polypropylene, polystyrene, poly-p-xylylene,
Examples thereof include polyacrylates, polymethacrylates, polyvinyl chlorides, polyvinylidene chlorides, polyvinyl acetates, fluororesins, polyacrylonitriles, polyvinyl ethers, diene-based polymers such as polybutadiene, and copolymers thereof. Examples of the polycondensation resin include polyamide, thermoplastic polyester, polycarbonate, polyphenylene oxide, and polysulfone, and examples of the polyaddition resin include thermoplastic polyurethane. Examples of the ring-opening polymerization resin include ethylene oxide, propylene oxide, alkylene oxide polymers such as tetrahydrofuran, polyacetal and the like.

Examples of (G) include waxes such as paraffin wax, microcrystalline wax, polymer wax, low molecular weight polyethylene, low molecular weight polypropylene, modified wax, beeswax, spermaceti and carnauba wax, dodecadioic acid and pyromellitic wax. Examples thereof include polybasic acids such as acids and trimellitic acid, their acid anhydrides and polyvalent metal salts, dimethyl sulfone, camphor, and urea.

The mixing ratio of (F) and (G) to (A) is such that (F) is usually 0 to 100 parts by weight of (A).
300 parts by weight, preferably 50 to 200 parts by weight, (G)
Is usually 0 to 200 parts by weight, preferably 10 to 100 parts by weight.

The present sealing material is mainly used by being applied to a steel plate joint portion and / or a steel plate edge portion of a vehicle body of an automobile body.

[0057]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. In the following description, "part" means part by weight and "%" means% by weight.

Production Example 1 900 parts of bisphenol A terephthalate with 2 mol of propylene oxide having a number average molecular weight of 2000 and a hydroxyl value of 56 was placed in a reaction vessel, dehydrated under reduced pressure at 140 ° C. for 2 hours, and then diluted with ethyl acetate (diluting solvent). ) 1100 copies and M
250 parts of DI was added and the reaction was carried out at 80 ° C. for 10 hours to obtain an isocyanate group-terminated urethane prepolymer (this will be referred to as “prepolymer (a-1)”). The isocyanate group content of the prepolymer (a-1) was 1.8%. In another container, polyvinyl alcohol (PVA)
[“PVA-235”, manufactured by Kuraray Co., Ltd.] 20 parts and water 7
The PVA solution (X) was obtained by adding 00 parts, stirring and dissolving. 300 parts of the prepolymer (a-1) was added thereto, and the dispersion was obtained by using an ultra disperser (manufactured by Yamato Scientific Co., Ltd.) and mixing for 1 minute at a rotation speed of 10,000 rpm. This dispersion was transferred to another reaction vessel, 12 parts of isophoronediamine and 1 part of dibutylamine were added,
The reaction was carried out at 50 ° C. for 10 hours. After completion of the reaction, filtration and drying were performed to obtain urethane resin fine particles (A-1). The number average molecular weight (by GPC measurement, the same applies hereinafter) of the urethane resin fine particles (A-1) is 40,000, Tg (by DSC measurement, the same applies below) is 90 ° C., and the SP value is 11.7.
The average particle size is 5 μm, and the ratio of major axis / minor axis is 1.0 to 1.5.
The ratio of the spherical particles in the range was 99% (observed with a microscope).

Production Example 2 160 parts of polypropylene glycol having a number average molecular weight of 400 and a hydroxyl value of 280 was placed in a reaction vessel, and the pressure was reduced.
After dehydration at 140 ° C. for 2 hours, 40 parts of ethyl acetate (diluting solvent) and 200 parts of MDI were added, and the reaction was carried out at 80 ° C. for 10 hours to prepare an isocyanate group-terminated urethane prepolymer [this was referred to as “prepolymer (a-2 ) ”And]]. The isocyanate group content of the prepolymer (a-2) was 8.0%. 200 parts of the prepolymer (a-2) was added to 720 parts of the PVA solution (X), and the rotation speed was 10, using an ultra disperser (manufactured by Yamato Scientific Co., Ltd.).
A dispersion was obtained by mixing at 000 rpm for 1 minute. This dispersion was transferred to another reaction vessel, 30 parts of isophoronediamine and 1 part of dibutylamine were added, and the reaction was carried out at 80 ° C. for 10 hours. After completion of the reaction, filtration and drying were carried out to obtain urethane resin fine particles (A-2). The urethane resin fine particles (A-
The number average molecular weight of 2) is 45,000, Tg is 65 ° C,
The SP value is 11.1, the average particle diameter is 6 μm, and the ratio of spherical particles having a major axis / minor axis ratio of 1.0 to 1.5 is 99%.
(Observation with a microscope).

Production Example 3 In a reaction vessel, 980 parts of an EO 8 mol adduct of octylphenol, 177 parts of triethylamine and 200 parts of toluene.
0 part was added, and 246 parts of benzoyl chloride was added dropwise with stirring. After the completion of the dropping, the reaction was completed at 110 ° C. for 1 hour. The reaction solution was washed once with water, twice with a 10% aqueous hydrochloric acid solution, twice with a 10% aqueous sodium hydroxide solution, and further with water several times with a separating funnel until the aqueous layer returned to neutral. Toluene is removed from the oil layer by a rotary evaporator (B-1) [in the general formula (1), Q is a phenyl group, A is an ethylene group, R is an octylphenyl group, and n is 8]. I got The plasticizer (B-
The purity of 1) was 98.8% (gas chromatograph).

Production Example 4 In a reaction vessel, dodecylphenol EO 6 mol adduct 9
61 parts and 184 parts triethylamine and 2000 parts toluene
Then, 255 parts of benzoyl chloride was added dropwise with stirring. After the completion of the dropping, the reaction was completed at 110 ° C. for 1 hour. The reaction solution was washed once with water, twice with a 10% aqueous hydrochloric acid solution, twice with a 10% aqueous sodium hydroxide solution, and further with water several times with a separating funnel until the aqueous layer returned to neutral. Toluene is removed from the oil layer by a rotary evaporator (B-2) [in the general formula (1), Q is a phenyl group, A is an ethylene group, R is a dodecylphenyl group, and n is 6]. I got The plasticizer (B-
The purity of 2) was 98.5% (gas chromatograph).

Examples 1 to 3 and Comparative Examples 1 and 2 [Preparation of Composition] The ingredients shown in Table 1 were uniformly mixed using a planetary mixer, and then degassed by stirring under vacuum for 1 hour. Thereby, the polyurethane paste compositions of Examples 1 to 3 and the compositions of Comparative Examples 1 and 2 were prepared.

[0063]

[Table 1] DOP; dioctyl phthalate ("DOP", manufactured by Daihachi Chemical Industry) DBP; dibutyl phthalate ("DBP", manufactured by Daihachi Chemical Industry) Filler (heavy carbon cal); heavy calcium carbonate ("NS-
100 ", made by Nitto Koka Kogyo)

[Evaluation Test] Next, for each composition,
The following items were tested.

(Paste Viscosity) The viscosity of each of the prepared compositions of Examples and Comparative Examples is B at 25 ° C.
It was measured with an H-type viscometer (manufactured by Tokyo Keiki) (rotation speed 20 rpm, rotor No. 7).

(Adhesion) Using a metal plate preliminarily subjected to cationic electrodeposition coating as a test piece, each composition was applied according to the method specified in JIS K6830, and then heated at 150 ° C. for 20 minutes to be baked. . Then, JIS K6
A shear adhesion test was performed according to the method specified in 830. The evaluation criteria of adhesion are as follows. ○: Complete cohesive failure △: Trace failure that partially causes interfacial failure ×: Complete interfacial peeling

(Adhesion after Immersion in Hot Water) In the same manner as above, each composition was coated, baked, and then immersed in warm water at 40 ° C. for 10 days. Then, a shear adhesion test was performed according to the method specified in JIS K6830. The evaluation criteria were the same as in the case of the above adhesion.

(Low Temperature Bending Test) Each composition prepared was heated at 140 ° C. for 30 minutes to be solidified, and then -30
After being held in a constant temperature bath at ℃ for 3 hours, quickly (within 2 seconds) 180
° Bend and check for flexibility. ◯: No cracks are generated Δ: Some cracks are generated ×: Cracks

(Physical properties of solidified product) Each composition was heated at 140 ° C. for 3 hours.
After heating for 0 minutes to solidify, the breaking strength, elongation and hardness (JIS A) at 25 ° C. were measured according to JIS K6.
It measured according to 301.

(Storage stability) Each composition was stored at 35 ° C. for 7 days, and then the viscosity at 25 ° C. was measured. (Manufacturer of viscometer, model number, measurement conditions are the same as the above-mentioned paste viscosity) Evaluation was performed by calculating the viscosity increase rate according to the following formula. Thickening rate = [(viscosity after storage−initial viscosity) / initial viscosity] × 100

(Long-term storage stability) Each composition was stored at 35 ° C.
After storage for 1 month, the viscosity at 25 ° C was measured. (The manufacturer, model number, and measurement conditions of the viscometer are the same as the above paste viscosity)
The evaluation was performed by calculating the thickening rate according to the following formula. Thickening rate = [(viscosity after storage−initial viscosity) / initial viscosity] × 100

(Dripping property) Each composition was applied in a semicircular bead shape having a diameter of 10 mm and a length of 100 mm on a test plate coated with cationic electrodeposition, and the test plate was held vertically at 140 ° C. for 30 minutes. After heating and taking out, the temperature was allowed to cool to room temperature, and then the flow distance was measured. Table 2 shows the test results of the above evaluation tests.

[0073]

[Table 2]

[0074]

The polyurethane paste composition of the present invention has the following effects. The increase rate of the viscosity of the polyurethane paste composition of the present invention is small over a long period of time, and therefore the storage stability is excellent over a long period of time, and the mechanical strength of the solidified product is also good. It also has the characteristics of the conventional polyurethane paste composition as follows. It has good paste fluidity at room temperature and is excellent in workability. It can be easily solidified by heating. The solidified product has good adhesiveness. The low temperature flexibility of the solidified product is good. It is a material with high environmental safety. From the above effect, the composition of the present invention is a composition for automobile sealing and a composition for undercoat,
It is useful as a sealing material, putty, and joint fixing material in the field of civil engineering and construction. Further, when the product of the present invention is used as a sealing material for automobiles, the sealing material is easily burnt and extinguished during recycling, so that the recycling performance of the body is improved.

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09K 3/10 C09K 3/10 Z (72) Inventor Hisato Kawakami 1 Sanyo Kasei Kogyo Co., Ltd. 11 Hitotsunomotocho, Higashiyama-ku, Kyoto In-company (72) Inventor Keiichi Yokouchi 1 Toyota-cho, Toyota-shi, Aichi F-term in Toyota Motor Corporation (reference) 4H017 AA04 AA31 AA39 AB03 AB17 AC01 AC02 AD05 AE05 4J002 AA014 AE005 BB015 BB034 BB134 BC034 BD044 BD104 BD124 BE044 BF024 BG044 BG053 BG054 BG104 BL014 CB004 CF004 CG004 CH022 CH074 CK021 CK031 CK041 CK051 CL004 CL063 CN034 DA017 DA067 DE087 DE237 DJ007 DJ027 DJ037 DJ047 DJ057 DL007 EH126 FA043 FA047 FD013 FD017FD023 FD026

Claims (11)

[Claims] 1. A paste composition comprising fine particles (A) comprising a polyurethane resin (a), a plasticizer (B) and a filler (C), wherein the plasticizer comprises an aromatic monocarboxylic acid monoester (B1). A polyurethane paste composition comprising: 2. The composition according to claim 1, wherein (B1) is an aromatic monocarboxylic acid monoester represented by the following general formula (1). Q-COO- (AO) n-R (1) [R is an alkyl group having 1 to 20 carbon atoms or 7 to 26 carbon atoms.
Of the above, A is an alkylene group having 2 to 4 carbon atoms, n is an integer of 1 to 30, and Q is optionally substituted by an alkyl group having 1 to 8 carbon atoms and / or a halogen and / or an alkoxy group. It is a phenyl group. ] 3. The composition according to claim 2, wherein in the general formula (1), A is an ethylene group and Q is a phenyl group. 4. The polyurethane paste composition has a temperature of 25 ° C.
The composition according to any one of claims 1 to 3, having a viscosity of 5,000 cP to 300,000 cP. 5. The glass transition temperature of (A) is -100 to 2
It is 00 degreeC, The composition in any one of Claims 1-4. 6. A composition according to any one of claims 1 to 5, a thermoplastic resin (F) and / or a crystalline substance which is solid at room temperature and is rapidly softened by heating at 80 ° C. or higher. A polyurethane composition comprising the compound (G) according to 1. above and having a hardness (JIS A) at 25 ° C. of 20 to 80. 7. A sealing material comprising the composition according to claim 1. 8. A sealing material in which the composition according to any one of claims 1 to 6 is carried on a support. 9. A solidified product obtained by heating and solidifying the composition or sealing material according to any one of claims 1 to 8. 10. The glass transition temperature of the solidified product is −70 ° C.
The solidified product according to claim 9, which has a temperature of -10 ° C. 11. An automobile body in which the sealing material according to claim 7 or 8 is applied to a steel plate joint portion and / or a steel plate edge portion of a vehicle body.