JP2000336339A - Polyurethane sealant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject sealant having a specific tack-free time and capable of providing a body sealer having physical properties excellent in elongation, heat resistance, etc., within a wide temperature range, especially low temperatures without substantially containing chlorine by including a specific amount of a specified recurring unit. SOLUTION: This two-part type polyurethane sealant has <=5 min tack-free time and is obtained by regulating the content of a recurring unit represented by the formula OCH2CH2CH2CH2 to 20-80 wt.% based on the total active hydrogen compounds and the apparent density within the range of 0.2-0.9 g/cm3. The above sealant is usually obtained by mixing a first liquid containing an isocyanate (e.g. diphenylmethane diisocyanate) with a second liquid which is a curing agent containing a polyol (ethylene glycol or propylene glycol).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-part urethane sealant for sealing a joint between a body of an automobile or the like and a door or the like.

[0002]

2. Description of the Related Art A body sealer is used for waterproofing, rustproofing, dustproofing and improving design of a steel plate joint portion of an automobile body or the like. Conventionally, PVC plastisol has been used as this body sealer. PVC plastisol is a one-component material and has good workability because it is a heat-cured material, but it has problems such as discoloration due to ultraviolet rays, cracking and peeling due to vibration, and the like. Furthermore, since dioxin is generated at the time of disposal and incineration, it is necessary to provide a detoxification facility at the time of incineration in order to prevent environmental pollution. On the other hand, although the urethane-based sealing material does not contain chlorine, its curability and physical properties are insufficient for use as a body sealer. For example, urethane-based sealing materials used as jointing materials for building materials have a long curing time of several hours, and are designed to follow the movement of the building by softening the hardness and increasing the elongation to about 500%. Also, the low-temperature properties and the heat resistance exceeding 100 ° C. are significantly reduced. In addition, urethane-based sealants used as adhesives for windshields and lamps of automobiles have a slow curing property and do not require heat resistance because they are used after the body painting line. It is a material whose emphasis is on emphasis and the elongation properties at low temperatures are not considered. Therefore, development of a sealing material for a body sealer that can be used for sealing a steel plate joint has been desired.

[0003]

SUMMARY OF THE INVENTION The present invention does not substantially contain chlorine, has a fast curing effect of being cured immediately after application, has no physical property deterioration at a baking temperature in a coating process of an automobile manufacturing line, and has an excellent property in a steel plate joint. There has been a long-awaited need for a body sealer that has a particularly large elongation as a material that can penetrate into small gaps, and after coating, has a waterproof property, a rust-proof property, and a physical property capable of withstanding repeated stress at low temperatures.

[0004]

Means for Solving the Problems In view of the above circumstances, the present inventors have intensively studied a method for producing a polyurethane sealant containing substantially no chlorine, and found that the method does not substantially contain chlorine and immediately after application. It has a fast curing that does not cause deterioration in physical properties at the baking temperature in the painting process of the automobile manufacturing line, enters into small gaps in the joints of steel plates, and after coating, it has waterproof, rustproof and repeated stress at low temperatures. A body sealer having particularly large elongation as a tolerable physical property was obtained, and the invention was completed. That is, the present invention provides the following (1) to (7). (1) A two-pack type polyurethane sealant having a tack-free time of 5 minutes or less, wherein the sealant has the general formula (1)

[0005]

Embedded image The content of the repeating unit is 20 to 80% by weight of the total active hydrogen compound, and the apparent density is 0.2 to 0.9.
g / cm ³ polyurethane sealant. (2) A polyurethane obtained by reacting the two-component polyurethane sealant according to (1) with a prepolymer (A) obtained from an active hydrogen compound and an isocyanate, and a curing agent (B) containing a polyol and a crosslinking agent. Sealant. (3) The molar ratio of isocyanate groups to active hydrogen (NCO
/ H ratio) in the range of 1.5 to 2.5, the polyurethane sealant according to (2), wherein the prepolymer (A) is used. (4) A polyurethane sealant wherein the crosslinking agent according to (2) or (3) is an amine compound. (5) The amine compound for a crosslinking agent according to (4), wherein the amine compound is at least one selected from the group consisting of diethyltoluenediamine, dithiomethyltoluenediamine, methylenedianiline, a polymeric product thereof, and orthotoluenediamine and metatoluenediamine. Is a polyurethane sealant. (6) The equivalent ratio (hydroxyl / amine group ratio) of the polyol and the amine crosslinking agent in the curing agent (B) is 50/50 to 5/95.
(4) The polyurethane sealant according to (4) or (5), wherein the curing agent (B) is used. (7) A polyurethane sealant for a body sealer, comprising the polyurethane sealant according to (1) to (6).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polyurethane for a body sealer according to the present invention will be described in detail. Hereinafter, unless otherwise specified, parts means parts by weight. The polyurethane for a body sealer according to the present invention is a two-pack type polyurethane sealant having a tack-free time of 5 minutes or less, and the content of the repeating unit represented by the general formula (1) in the sealant is all active hydrogen. 20-80 wt% in the compound
And the apparent density is in the range of 0.2 to 0.9 g / cm ³ . This two-pack type polyurethane sealant is usually obtained by mixing a first liquid containing isocyanate and a second liquid which is a curing agent containing a polyol. It can also be done. First, a method for producing these two-pack type polyurethane sealants and production of raw materials thereof will be described.

[Production method of two-pack type polyurethane sealant] The two-pack type polyurethane sealant used in the present invention has a tack-free time of 5 minutes or less, and a repetition represented by the general formula (1) in the obtained sealant. The content of the unit is adjusted to 20-80 wt% of the total active hydrogen compound,
The first liquid containing an isocyanate and the second curing agent (B) containing a polyol are usually produced so that the apparent density is in the range of 0.2 to 0.9 g / cm ³ .
It is obtained by mixing with a liquid.

{First Liquid} As the isocyanate contained in the first liquid, diphenylmethane diisocyanate (M
DI), aromatic diisocyanates such as tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), tetramethyl xylylene diisocyanate (TMXDI), and isophorone diisocyanate (IPD).
Any aliphatic diisocyanate such as I), hexamethylene diisocyanate (HDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), and hydrogenated diphenylmethane diisocyanate (hydrogenated MDI) may be used as long as it is used for ordinary urethane. Prepolymerization stabilizes the curability and physical properties of the resulting sealant even if the curing conditions of the sealing material fluctuate, so use isocyanate and an active hydrogen compound in addition polymerization and use a prepolymer having a terminal isocyanate group. Is preferred.

(Prepolymer (A)) The prepolymer (A) used in the present invention is a reaction product of an isocyanate and an active hydrogen compound, and usually has an isocyanate terminal. Although there is no particular limitation on the production method, usually, the isocyanate and the active hydrogen compound are collectively blended or a component to be a terminal is charged first, and the other is added later, and then the 10
It is obtained by reacting at 120 ° C. for 1 to 150 hours. In order to speed up the reaction, a known catalyst may be added and reacted for production. When producing the prepolymer (A), the molar ratio of isocyanate groups to active hydrogen (NCO / H ratio) can be arbitrarily selected in accordance with the required hardness of the polyurethane, but in order to further improve workability. Is preferably 1.5 or more, and more preferably 2.5 or less in order to promote the development of fast curing properties and initial physical properties. In the case of curing by prepolymerization, the polymer can be polymerized in a shorter period of time, whereby fast curing and stable physical properties can be obtained. The average molecular weight is not particularly limited, but is generally 300 to 500
00, preferably 500-20000, most preferably 700-10000
It is. The prepolymer (A) preferably has a repeating unit represented by the general formula (1).

(Isocyanate used for producing prepolymer (A)) As the isocyanate to be reacted with the active hydrogen compound, an isocyanate used in a usual polyurethane resin composition can be used. Preferably, a polyisocyanate having two or more molecular terminal isocyanate groups in the molecule is used. For example, tolylene diisocyanate (TDI), hydrogenated tolylene diisocyanate, diphenylmethane diisocyanate (MDI), polymeric MDI (P
MDI), xylylene diisocyanate (XDI), aromatic isocyanates such as 1,5-naphthalenediisocyanate (NDI), aliphatic isocyanates such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI),
Examples include alicyclic polyisocyanates such as hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), norbornane diisocyanate methyl (NBDI), and carbodiimide-modified isocyanates and isocyanurate-modified isocyanates of the above-mentioned isocyanates. Of these, use of TDI, MDI and PMDI is particularly preferred, and these may be used in combination of two or more. These may be used alone when producing the prepolymer (A), or a plurality of them may be used in combination as needed.

(Active Hydrogen Compound Used in Prepolymer (A) Production) An active hydrogen compound used in a usual polyurethane resin composition can be used. The active hydrogen compound used in the present invention is a compound having active hydrogen that reacts with isocyanate such as a polyol (a compound having two or more hydroxyl groups at molecular terminals), a thiol, and an amine compound. Examples of the polyol include polyhydric alcohols having relatively low molecular weight, polyether polyols, polyester polyols, polyether polyols, and modified products of polyester polyols. More specifically, relatively low molecular weight polyhydric alcohols include ethylene glycol (EG) and diethylene glycol (DE).
G), propylene glycol (PG), dipropylene glycol (DPG), 1,3-butanediol (1,3-B
D), dihydric alcohols such as 1,4-butanediol (1,4-BD), 4,4'-dihydroxyphenylpropane, 4,4'-dihydroxyphenylmethane, glycerin, 1,1,1-trimethylol Examples include trihydric alcohols such as propane (TMP) and 1,2,5-hexatriol, and polyhydric alcohols having a valency of 4 or more such as pentaerythritol, glucose, sucrose, and sorbitol.

As the polyether polyol, a polyether polyol obtained by addition-polymerizing one or more of ethylene oxide, propylene oxide, butylene oxide, etc. to one or more polyhydric alcohols having a relatively low molecular weight, and And polytetramethylene ether glycol (PTMEG) obtained by ring-opening polymerization of tetrahydrofuran. As the polyester polyol, one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerin, trimethylolpropane and the like or other low molecular polyols and glutaric acid, adipic acid, sebacic acid, terephthalic acid And polyester polyols obtained by condensation polymerization with one or more kinds of low-molecular dicarboxylic acids or oligomeric acids, or other low-molecular dicarboxylic acids or oligomeric acids, and ring-opening polymerization such as caprolactone.

Examples of modified polyether polyols or polyester polyols include polymer polyols obtained by graft-polymerizing ethylenically unsaturated compounds such as acrylonitrile, styrene, methyl methacrylate and the like to the above-mentioned known polyether polyols or polyester polyols. No. Examples of the diamine compound include aliphatic diamines such as ethylenediamine and aromatic diamines. Among active hydrogen compounds, polyols are preferable, and polyhydric alcohols and polyethers having a relatively low molecular weight are more preferable because the water resistance of the resulting sealant having a low material viscosity is further improved. Those having the indicated structure are most preferred.
When PTMEG is used, it is desirable to mix PTMEG in the prepolymer at a high rate from the viewpoint of preventing the hardener from solidifying in winter. These active hydrogen compounds may be used alone or in combination as necessary.

{Second Liquid} The second liquid is usually called a curing agent because curing is started by mixing with the first liquid. The curing agent (B) comprises a polyol and a crosslinking agent,
If necessary, a thixotropic agent, a catalyst, a foam stabilizer, and a foaming agent can be used in combination. Also, a plasticizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antioxidant, a pigment and a dye coloring agent, a dispersant, etc., which are used in ordinary urethane molding within a range not impairing the effects of the present invention. Various other additives can be blended. These other additives may be partially or entirely incorporated into the first liquid as long as the effects of the present invention are not impaired.

(Polyol) The polyol used for the curing agent (B) may be the same as or different from that used for the first liquid, and they may be used alone or in combination. Examples of the polyol include polyhydric alcohols having relatively low molecular weight, polyether polyols, polyester polyols, polyether polyols, and modified products of polyester polyols. More specifically, relatively low molecular weight polyhydric alcohols include ethylene glycol (EG) and diethylene glycol (DE).
G), propylene glycol (PG), dipropylene glycol (DPG), 1,3-butanediol (1,3-B
D), dihydric alcohols such as 1,4-butanediol (1,4-BD), 4,4'-dihydroxyphenylpropane, 4,4'-dihydroxyphenylmethane, glycerin, 1,1,1-trimethylol Examples include trihydric alcohols such as propane (TMP) and 1,2,5-hexatriol, and polyhydric alcohols having a valency of 4 or more such as pentaerythritol, glucose, sucrose, and sorbitol.

As the polyether polyol, a polyether polyol obtained by addition-polymerizing one or more kinds of ethylene oxide, propylene oxide, butylene oxide and the like to one or more kinds of relatively low molecular weight polyhydric alcohols and And polytetramethylene ether glycol (PTMEG) obtained by ring-opening polymerization of tetrahydrofuran. Polyester polyols include one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerin, 1,1,1-trimethylolpropane, and other low molecular polyols, and glutaric acid, adipic acid And polyester polyols obtained by condensation polymerization with one or more kinds of sebacic acid, terephthalic acid, isophthalic acid, dimer acid or other low-molecular dicarboxylic acids or oligomeric acids and ring-opening polymerization of caprolactone. Can be Examples of the modified product of the polyether polyol or the polyester polyol include a polymer polyol obtained by graft-polymerizing an ethylenically unsaturated compound such as acrylonitrile, styrene, or methyl methacrylate to the known polyether polyol or polyester polyol. The amount used may be appropriately set according to the desired physical properties of the product, but is usually 5 to 30 parts in 100 parts of the curing agent (B).

(Crosslinking agent) As the crosslinking agent used for the curing agent (B), those known as crosslinking agents for urethane can be used. For example, low molecular alcohols such as ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol can be used. , Tripropylene glycol, butanediol, pentanediol, hexanediol,
1,3-butanediol, 1,4-butanediol, dihydric alcohols such as 4,4'-dihydroxyphenylpropane, 4,4'-dihydroxyphenylmethane, glycerin, 1,1,1-trimethylolpropane, 1 Polyhydric alcohols such as 2,5,5-hexanetriol and pentaerythritol can be used, but amine crosslinking agents are preferred for improving the curing speed. Examples of the amine-based crosslinking agent include methylene bisorthochloroaniline (MBOCA), diethyltoluenediamine, dithiomethyltoluenediamine, methylenedianiline and its polymeric products, orthotoluenediamine,
Metatoluenediamine and the like can be mentioned, and polymeric products of diethyltoluenediamine and methylenedianiline, which react quickly with isocyanate, are particularly preferred. The amount used may be appropriately set according to the desired physical properties of the product, but is usually 5 to 25 parts in 100 parts of the curing agent (B).

(Thixotropic agent) Thixotropic agents include aliphatic amide wax, polytetrafluoroethylene resin (P
Organic fillers such as TFE), surface-treated calcium carbonate of fine particles treated with higher fatty acids and fatty acid esters, and inorganic fillers such as silica and bentonite. Among them, the surface-treated calcium carbonate is preferable because the change in thixotropic property with respect to the change in the liquid temperature is small. The thixotropic agent may be appropriately adjusted and added so that the mixed liquid of the first liquid and the second liquid does not sag even on a vertical surface. Generally, it is 40 parts to 70 parts in 100 parts of (B).

(Catalyst) The catalyst used in the present invention is, for example, an organotin compound such as dibutyltin dilaurate, dioctyltin dimaleate, stannous octylate, dibutyltin oxide, or tetrabutyl titanate. Organic titanium compounds, lead naphthenate, organic lead compounds such as lead octylate, organic metal catalysts such as organic bismuth compounds such as bismuth neodecanoate and bismuth octylate, triethylenediamine, triethylamine, tetramethylenediamine, N-methylmorpholine, Tertiary amines such as N, N-dithymethanolamine can be used alone or in combination. The amount to be used may be appropriately set according to the intended physical properties of the product.
0.1 to 2 parts per part.

(Blowing Agent) As the blowing agent used in the present invention, any of a physical blowing agent and a chemical blowing agent can be used.
Specifically, the physical foaming agent includes Freon, alternative Freon, methylene chloride and the like, and the chemical foaming agent includes water and the like. Among them, it is preferable to use water from the viewpoint of environmental protection, and it is particularly preferable to use distilled water or ion-exchanged water. The amount used can be appropriately selected so that the resin density becomes a predetermined apparent density. 0.2 apparent density
In order to keep it at 0.9 g / cm ³ , the amount used can be extremely small. For example, 0.01 part to 1.0 part in 100 parts of (B)
Department. In such a case, the first liquid, the second liquid,
It is necessary to take into account the content of a component that can act as a foaming agent contained in the liquid as an addition amount. Such components include, for example, water content.

(Foam stabilizer) As the foam stabilizer used in the present invention, materials used for urethane molding can be used. Since it is preferable to increase the proportion of closed cells for the purpose of imparting waterproofness, it is preferable to use a brand for forming closed cells, which has a strong foam-regulating power usually used for rigid foams. For example, for example, L-542 manufactured by Nippon Unicar
0, SZ-1627, TG-8462 manufactured by Goldschmidt, and the like. The amount used may be appropriately set in accordance with the intended physical properties of the product, but is usually 0.1 to 100 parts (B).
1 to 2.0 parts.

{Production equipment for polyurethane sealant, etc.}
The polyurethane sealant is obtained by mixing a first liquid containing isocyanate and a second liquid which is a curing agent (B) containing a polyol. The obtained sealant may be separately applied to the target by a coating device, but is usually applied directly to the target after mixing. As equipment for stirring and mixing for producing the polyurethane sealant, pumps having quantitative properties for feeding raw materials, for example, a gear pump, a combined use of a plunger pump and a throttle valve, and the like, a mechanical rotary mixer for mixing, A static mixer or the like can be used. Since a fast-curing material is used, a mechanical rotary mixer system having a small-volume mixing chamber is desirable. The mixing ratio of the first liquid and the second liquid can be appropriately set according to the required physical properties of the product, but usually the ratio of the two is 1: 3 to 3: 1 by weight. When the polyol used for at least one of the prepolymer (A) and the curing agent (B) contains polytetramethylene ether glycol, the total amount of the polytetramethylene ether glycol and 20 to
It is preferable to adjust and mix each raw material composition so as to be 80% (on a hydroxyl equivalent basis).

[Two-component polyurethane sealant] The two-component polyurethane sealant used in the present invention has a tack-free time of 5 minutes or less. When the content of the repeating unit represented by the general formula (1) in the obtained sealant is 20
~ 80wt%, apparent density 0.2 ~ 0.9g /
cm ³ . When producing a polyurethane sealant, it is preferable to foam using a foaming agent, since the waterproofness and the rust prevention effect are improved. When the polyurethane sealant thus obtained is a foam, the ratio of closed cells in the cells is more preferably 50% or more. Further, the polyurethane sealant is suitable as a sealant for sealing a joint of a body of an automobile or the like and a door or the like. Other materials may be used in combination as long as the effects of the present invention are not impaired. The polyurethane sealant obtained by the above-mentioned method has a tack-free time of 5 minutes or less and exhibits fast curing, and the baking temperature (150 ° C) in the coating process
After exposing for 1 and 2 hours at 25 ° C., the elongation measured after returning to 25 ° C. is 150% or more, and shows an elongation of 50% or more even at -30 ° C. below the freezing point. 25 ° C. In 20 kgf / cm ² or more in tensile strength, indicating a sub-zero eg -30 ° C. even 40 kgf / cm ² or more. Adhesion to steel plate is good, and if there is a gap in the joint, it is thought that it can withstand repeated stress by foaming and entering into fine parts, and at the same time painting with steel plate Can also.

[0024]

According to the present invention, a polyurethane sealant containing a specific range of a specific repeating unit can be used in a wide temperature range.
In particular, a body sealer having excellent physical properties such as elongation at low temperatures and heat resistance was obtained. Further, by using the foam material, the sealing material can be filled to every corner of the spot welded portion, and rust prevention and waterproof performance can be improved.

[0025]

Example 1) Preparation of used materials Preparation of prepolymer (A-1): 180 g of PTMEG-1000 (OHv = 112, average number of functional groups = 2, manufactured by Dupont) in a separable flask equipped with a stirrer, dipropylene 46.3 g of glycol, propylene triol MN-400 (OHv = 4
10, average functional groups = 3, 6.7 g of Mitsui Chemicals) and TDI-100
(Manufactured by Mitsui Chemicals, Inc.) at a rate of 174 g. Under a stream of nitrogen
After reacting at 80 ° C for 4 hours and aging at room temperature for 1 day, NCO% = 9.
2. A prepolymer having a viscosity (cp / 25 ° C.) of 30,000 was obtained. The NCO / H ratio during the reaction is 1.8.

Preparation of prepolymer (A-2): 400 g of PTMEG-1000 and TDI-80 (manufactured by Mitsui Chemicals, Inc.) using the same apparatus as in (A-1)
Was charged at a rate of 174 g and reacted at 80 ° C. for 3 hours. After aging for 1 day, the analysis value was NCO% = 8.8, viscosity (cp / 25 ° C.) = 16,000.
The NCO / H ratio during the reaction is 2.5.

Preparation of prepolymer (A-3): A polypropylene diol having a molecular weight of 5000 (OHv = 2
2.4, manufactured by Mitsui Chemicals, Inc.) and 174 g of TDI-80. The reaction was performed at 80 ° C for 4 hours under a nitrogen stream.
After aging, a prepolymer having NCO% = 9.2 and viscosity (cp / 25 ° C.) = 3,000 was obtained. The NCO / H ratio during the reaction is 8. Table 1 shows the preparation results of the prepolymer (A).

[0028]

[Table 1]

Preparation of curing agent (B-1): diethyltoluenediamine (DETDA, manufactured by Albemarle) was used as an amine crosslinking agent.
419 g, terminal EO cap triol EP-550N (OHv = 54, manufactured by Mitsui Chemicals) 1990 g, amine polyol NS-100 (OHv = 345, manufactured by Mitsui Chemicals, Inc.) 159 g, water 9 g, dibutyltin dilaurate (DBTDL) as a catalyst 25g, amine catalyst (Kaorizer N
o.12) as a plasticizer, dinisononyl adipate (DIN
A) 2863 g and surface-treated calcium carbonate MS-100M (fatty acid and resin acid treated product, 8500 g, manufactured by Maruo Calcium Co., Ltd.) were charged into a dissolver mixer manufactured by Inoue Mfg.
The mixture was stirred and mixed under the conditions of m for 1 hour. Next, a foam stabilizer L-5420
After adding 20 g (manufactured by Nippon Unicar), the mixture was stirred and mixed for 15 minutes to obtain a curing agent (B-1) having a thixotropic property. The ratio of the thixotropy was 4 using a B-8H rotational viscometer, and the ratio was 1 rotation to 10 rotations. The polyol / amine equivalent ratio at this time is 20/80.

Preparation of curing agent (B-2): Polymeric product MDA-150 of methylene dianiline which is a liquid aromatic amine as an amine crosslinking agent (amino group content = 15.5 or more, viscosity = 1 to 30,000 cp)
s / 40 ° C, Mitsui Chemicals) 1538 g, PTMEG-1000 1000 g,
Other raw materials were prepared in the same manner as in Example 1 using the amounts shown in Table-2. The polyol / amine equivalent ratio at this time is 25.
/ 75.

Preparation of curing agents (B-3 to B-5): Preparation was carried out using the same equipment as in (B-1) under the same conditions, using the materials having the composition shown in Table-2.
Table 2 also shows the polyol / amine ratio.

Preparation of curing agent (B-6): Preparation was carried out using the same equipment as in (B-1) and under the same conditions, using the materials having the composition shown in Table-2.
Diol-700 is a polypropylene diol with a molecular weight of 700 (OHv = 16
0, manufactured by Mitsui Chemicals, Inc.). Table 2 shows the polyol / amine ratio.
It is 70/30. Table 2 shows the preparation results of the curing agent (B).

[0033]

[Table 2]

(Evaluation and test methods) Gelation time: Predetermined amount of prepolymer (A) liquid and curing agent (B)
Measure the solution in a beaker, vigorously stir with a spatula,
Time until liquid loses fluidity.

TFT: Abbreviation of tack free time, which is the time from mixing of the prepolymer (A) and the curing agent (B) until the resin does not transfer to the finger even when the cured product surface is touched.

-Dripping resistance: The coating is applied to a slump test jig for a sealing material which has been made vertical, and the state of dripping is observed. 1m
Less than m was rated as ◎, less than 1-2 mm as Δ, and more than 2 mm as ×.

Curing conditions of the resin: After curing to TFT at room temperature, the resin was cured at 100 ° C. for 1 hour, then returned to room temperature and cured for 1 day. Heat resistance test at 150 ° C in addition to RT (room temperature), -30 degree atmosphere
(1 and 2 hours) and after the boiling test (1 hour)
After standing for a day, a physical property test was performed.

Physical property test: carried out in accordance with JIS K-6301. The hardness is measured using a JIS-A type hardness tester, the tensile test is performed using A & D Tensilon, the speed is 500 mm / min, the test specimen is a JIS-2 dumbbell, and the tear strength is B type. I went in. As a result, hardness (JIS-A), tensile strength (Ts: kgf / cm
2), elongation (EL:%), and tear strength (Tr: kgf / cm) were measured.

・ Adhesion test with iron plate (180 ° peel test): JI
S G-3141 (SPCC, SD) Cationic electrodeposition coating method Apply the material on an electrodeposition coated iron plate of U600 (manufactured by Test Piece Co., Ltd.) and cure it under the above conditions. The tensile strength (kgf / in) was measured at a speed of / min.

Rust prevention test: After applying a cross-cut to the above-mentioned electrodeposited iron plate to reach the base iron plate, a sealer material was applied.
Cure at 25 ° C for 7 days. After immersing the test piece in water at 40 ° C. for 7 days, the condition of the cross cut portion is observed. The sample having red rust was evaluated as x, the sample with metallic luster remained as ○, and the sample with no metallic luster but no red rust was evaluated as Δ.

Waterproof test: The test was carried out according to the "water permeability test" described in JIS A-6910 (multi-layer finish coating material). The test sample was prepared by using a Toray polyester spunbond (H50901, thickness = 0.31 mm, basis weight = 90 g / m2, air permeability = 120 c as a base).
c / cm2 / sec), apply a sealer material to a thickness of 5 mm, and then apply an acrylic urethane paint (Color Top SS, manufactured by Asia Industry Co., Ltd.)
Was applied at a rate of 150 g / m 2 and cured at 25 ° C. for 14 days. Next, a funnel was set up on the surface of the sealer, and the periphery was fixed with a silicone sealant, and the operation was performed at a water head of 250 mm. After 24 hours, the case where the water head height was 230 mm or more was evaluated as ○, 200 to 229 mm as Δ, and less than 200 mm as X.

Example 1 As a prepolymer (A), (A-
100 parts by weight of 1) and 150 parts by weight of (B-1) as a curing agent for (B), and molding is performed using a machine made by Toho Machinery (gear pump feed, mechanical mixing head / solvent cleaning type) did.
In this case, the PTMEG content in the resin is 47.6%, the polyol / amine ratio in the curing agent is 20/80, and the NCO Index (NCO / H) is 1.1.
It is. The composition was applied onto an electrodeposition-coated iron plate and a Teflon-coated mold, and the adhesion and physical properties were measured. As a result, the reactivity was 1 minute for the gel time, 3 minutes for the tack-free time at 25 ° C, and the physical properties were hardness (JIS-A) of 78 and tensile strength (T
s) 21 kgf / cm2, elongation (EL) 200%, tear strength (Tr) 16 kgf
/ cm, the cured product density was 0.68 g / cm3, and the cross section of the sealer was observed. As a result, "fine bubbles" were formed, and the whole was foamed in a homogeneous state. The curability was fast, the physical properties were good, and the material was well-balanced. The properties at -30 ° C showed a tensile strength of 64 kgf / cm2 and an elongation of 52%. The results of a heat resistance test at 150 ° C x 1 and 2 hours assuming an automotive paint line show that the tensile strength is 21kgf / cm2 and the elongation is 165%, which is not so different from the physical properties at room temperature. It was thought that there was not. After further immersion in boiling water for 1 hour, it was dried for 7 days, and its physical properties were measured to examine the degree of deterioration. The physical properties were not so different from those at room temperature, and were good results. in addition,
In the adhesion test with the electrodeposition iron plate, 18
The material was broken in the 0 degree peel test, and the strength was 2.5 kgf / in or more. As a result of the rust prevention test, the metallic luster remains,
As a result of the waterproof test, the water head was 240 mm and the result was “○”. As described above, this material was suitable as an automobile body sealer.

Example 2 (A-1) was used as a prepolymer in an amount of 100
Parts by weight, and 150 parts by weight of (B-2) as a curing agent, were molded using a two-part static mixer with 20 stages for mixing the two liquids using a gear pump for liquid feeding. in this case,
The PTMEG content in the resin is 57.6%, the polyol / amine ratio is 25/75, and the NCO Index is 1.1. A molding test was performed in the same manner as in Example 1. As a result, the reactivity is tack free time at room temperature for 3 minutes, the physical properties are hardness (JIS-A) 68, tensile strength 18 kg
f / cm2, elongation 172%, tear strength 12 kgf / cm, cured product density 0.65 g / cm3, and observing the sealer cross section,
"Fine bubbles" were formed and the whole foamed in a homogeneous state. The curability was fast, the physical properties were good, and the material was well-balanced. The physical properties at -30 ° C showed a tensile strength of 51 kgf / cm2 and an elongation of 50%. As a result of a heat resistance test at 150 ° C x 1 and 2 hours assuming an automotive coating line, the tensile strength is 18kgf / cm2 and the elongation is 165%, which is not so different from the physical properties at room temperature. It is thought that there is not. Further, after being immersed in boiling water for one hour and dried, the degree of deterioration was examined. The physical properties were not so different from those at room temperature, and were good results. In addition, in the adhesion test with the electrodeposition coated iron plate, the material was destroyed by the 180 degree peel test with no surface treatment and the strength was
It was more than 2.5kgf / in. The result of the rust prevention test was “○”, and the waterproofness was “○” with a head of 245 mm. As described above, this material was suitable as an automobile body sealer.

Example 3 and Example 4 A sealer was prepared in the same manner as in Example 1 except that the raw materials shown in Table 3 were used.
The results as shown in Table 3 were suitable for a body sealer for automobiles as in Examples 1 and 2. In each case,
"Fine bubbles" were formed and the whole was foamed in a homogeneous state, and the results of the rustproofing and waterproofing tests were "O".

(Comparative Example 1) 10 parts of (A-3) was used as a prepolymer.
0 parts by weight, as a curing agent (B-5) 150 parts by weight,
The molding was performed by the same machine and molding method as in Example 1. In this case, the PTMEG content in the resin is 6.5%, the polyol / amine ratio is 25/75, and the NCO Index is 1.1. As a result, the reactivity was such that the tack-free time was as long as 15 minutes at room temperature, and the time required for curing was long, causing sagging. The sag resistance was 1.7 mm, and the evaluation was △. This is presumably because the NCO / H ratio of prepolymer A-3 was as high as 8, free TDI monomer remained, chain elongation was delayed, and tack free time was lengthened. In addition, the physical properties were that the hardness (JIS-A) was 78, but the tensile strength was 12 kgf / cm2, the elongation was 130%, the tear strength was 9.5 kgf / cm, and the cured product density was 0.67 g / cm3. When the cross section of the sealer was observed, it was found that "rough air bubbles" were formed and the whole was foamed in an uneven state. The required curability and physical properties were insufficient. The properties at -30 ° C were such that the tensile strength was 65 kgf / cm2 and the elongation was 20%. 150 assuming an automotive painting line
The result of the heat test at 1 ℃ and 2 hours shows that the tensile strength is 9kgf / c
m2 and elongation were 60%, which tended to deteriorate. Further, after being immersed in boiling water for 1 hour and dried, the degree of deterioration was examined. However, the physical properties were lowered and deterioration was observed. In the adhesion test with the electrodeposition coated iron plate, the material was broken and the strength was 1.0 kgf / in or more. However, it was lower than that of the curable and physical co-chloride visol. The result of the rust prevention test is probably because it took time to cure,
Since bubbles were connected from the base to the surface and red rust was generated partially, the evaluation was "x", the waterproof performance was 50 mm water head
And "x".

(Comparative Example 2) 10% of (A-1) was used as a prepolymer.
0 parts by weight, as a curing agent (B-6) 150 parts by weight,
Molding was carried out by the same machine and molding method as in Example 2. In this case, the PTMEG content in the resin is 51%, the polyol / amine ratio is 70/30, and the NCO Index is 1.1. As a result, the reactivity was such that the tack-free time was as long as 30 minutes at room temperature, the dripping became large, and the evaluation was 5 mm and x. This is probably because the amine ratio in the curing agent was low. Physical properties are hardness (JIS
-A) was as low as 10, tensile strength was 2.1 kgf / cm2, elongation was 50%, tear strength was 0.9 kgf / cm, and cured product density was 0.1 g / cm3.
When the cross section of the sealer was observed, it was found that "rough air bubbles" were formed, and the whole was foamed in an uneven state. In particular, it is considered that the physical properties were reduced due to the reduced density due to foaming. A heat resistance test at −30 ° C., 150 ° C. × 1 and 2 hours, and a degree of deterioration by a 1-hour immersion test in boiling water were examined, but all were low values. Both curability and physical properties were significantly insufficient. In addition, in the rust prevention test, bubbles gathered due to the slow reaction, and rust was generated in the part where large bubbles were present. Was 200 mm and "x". Table 3 shows the results of the molding test.

[0047]

[Table 3]

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H017 AA04 AA31 AB06 AC16 AC19 AD05 AE05 4J034 BA05 CA04 CA05 CA15 CB03 CB04 CB05 CB07 CC03 CC08 CC12 CC61 CC67 CD04 CD08 CD13 DB04 DF12 DF14 DF16 DF20 DF21 DG03 DG04 DG04 DG04 DQ15 DQ16 DQ18 HA01 HA02 HA07 HC03 HC12 HC13 HC22 HC46 HC61 HC64 HC67 HC71 HC73 JA41 JA42 KA01 KB04 KC16 KC17 KD02 KD04 KD11 KD12 KD21 KE02 NA01 NA02 NA03 NA05 QA03 QA05 QB01 RA08 RA11 4J038B03 DG05 DG05 PC02 4J040 EF051 EF061 EF111 EF131 EF321 JA13 LA01 LA04 LA05 LA06 LA07 LA08 MA03 MB11 NA16

Claims (7)

[Claims] 1. A two-pack type polyurethane sealant having a tack-free time of 5 minutes or less, wherein the sealant has the following general formula (1): The content of the repeating unit is 20 to 80% by weight of the total active hydrogen compound, and the apparent density is 0.2 to 0.9.
g / cm ³ , a polyurethane sealant characterized by the following range: 2. The two-part polyurethane sealant according to claim 1, which is obtained by reacting a prepolymer (A) obtained from an active hydrogen compound and an isocyanate with a curing agent (B) containing a polyol and a crosslinking agent. A polyurethane sealant characterized by being obtained. 3. The prepolymer (A) according to claim 2, wherein the prepolymer (A) produced with the molar ratio of isocyanate groups to active hydrogen (NCO / H ratio) in the range of 1.5 to 2.5 is used. Polyurethane sealant. 4. A polyurethane sealant, wherein the crosslinking agent according to claim 2 is an amine compound. 5. The amine compound for a crosslinking agent according to claim 4, wherein the amine compound is at least one selected from the group consisting of diethyltoluenediamine, dithiomethyltoluenediamine, methylenedianiline or a polymeric product thereof, and orthotoluenediamine and metatoluenediamine. A polyurethane sealant, which is an amine compound. 6. An equivalent ratio (hydroxyl / amine group ratio) of the polyol and the amine crosslinking agent in the curing agent (B) of 50/50 to 5
The polyurethane sealant according to claim 4, wherein a curing agent (B) having a ratio of / 95 is used. 7. A polyurethane sealant for a body sealer, comprising the polyurethane sealant according to claim 1.