JPH09221628A - Two-pack solventless urethane-based resin coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject coating agent good in smoothness when applied to objects, high in adhesive force, excellent in surface protecting ability as well as capable of giving coating films with expected mechanical strength and flexibility, comprising a specific polyol component, a crosslinking agent, and others. SOLUTION: This coating agent comprises (A) a polyisocyanate component (pref. consisting mainly of diphenylmethane diisocyanate-based polyisocyanate), (B) a polyol component (primary OH group-contg. polyol accounts for >50wt.%), (C) a crosslinking agent (diethyltoluenediamine), and (D) a catalyst (pref. a bismuth-based compound). It is preferable that the primary OH group-contg. polyol. in the component B is a mixture of high-OH value polyol >100 (esp. >=110) in OH value (x) and low-OH value polyol with its OH value lower than (x) in the weight ratio of (6:4) to (9:1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-component solventless urethane-based resin coating material suitable for use for the purpose of surface protection of objects such as plastic foams, plastics moldings, metals and wood materials. It is a thing.

[0002]

2. Description of the Related Art The strength of a foam has been increased by forming a reinforcing film on the surface of the plastic foam. A urethane resin coating agent is suitable as the reinforcing film forming agent.

Japanese Examined Patent Publication (Kokoku) No. 3-67107
No. 147329), a main agent (diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate or a modified product thereof), a curing agent (containing 50% or more primary hydroxyl groups, and an OH value of 100 mg KO).
Room-temperature curing type that contains 50% or more of H / g or less polymer polyol, crosslinking agent (polyamines, polyhydric alcohols or alkanolamines), and catalyst (tertiary amine or organometallic compound) High-reaction polyurethane stock solution, using a high-pressure spray device, 30-210kg / c
A method of strengthening a foam protective body is shown, which is sprayed on the surface of the protective body with a discharge pressure of m2.

Among the crosslinking agents, those specifically mentioned as polyamines are ethylenediamine, hexamethylenediamine, p-phenylenediamine, 3,3'-.
Dichloro-4,4'-diaminodiphenylmethane, 3,
3'-dimethyl-4,4'-diaminodiphenylmethane, 3,5,3 ', 5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,5-diethyl-3',
5'-diisopropyldiaminodiphenylmethane, 3,
5,3 ′, 5′-tetraisopropyldiaminodiphenylmethane, which does not include polyamine as a cross-linking agent in Examples, but in Comparative Example 1, 4,4′-diamino-3,3 ′. -Using dichlorodiphenylmethane. Among the catalysts, those specifically referred to as an organometallic compound are lead octoate, lead naphthenate, tin octoate, and dibutyltin dilaurate,
An example using dibutyltin dilaurate is given in the examples.

Japanese Unexamined Patent Publication (Kokai) No. 7-179634 discloses a method of forming a reinforced coating of a polyurethane elastomer on the surface of a polystyrene foam, using a two-component reactive solventless urethane raw material as the polyurethane elastomer raw material, It is disclosed that the polystyrene foam surface is spray-applied and the maximum temperature of the polystyrene foam between the time of application and the completion of curing is in the range of 30 to 80 ° C.

This publication describes that bifunctional diamines and diols are used as the chain extender, and glycerin, sorbitol and the like are used as the crosslinking agent. The primary or secondary di- or polyamines have both functions of a chain extender and a cross-linking agent, and 3,3'dichloro-, which has heretofore been widely used as such.
There is also a description that 4,4'diaminodiphenylmethane can be used. The catalyst may be blended if necessary, but there is no further description. Examples include:
An example using MDI prepolymer as the polyisocyanate, polypropylene glycol as the polyol, and 1,4-butanediol as the chain extender is shown.

[0007]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 3-67107
The method for strengthening the foamed protective body of the publication is actually adopted mainly for strengthening polystyrene foamed bodies such as fish boxes, and is considered to be effective in preventing dents and scratches,
There is still room for improvement in terms of smoothness that affects the finished appearance and adhesion to the foam, especially in terms of maintaining adhesion when impacted.

The method for forming a reinforced coating disclosed in Japanese Patent Application Laid-Open No. 7-179634 is intended to increase the adhesion to the foam by limiting the maximum temperature of the foam surface during the coating formation process. I am dissatisfied with this point and need further improvement.

Under such a background, the present invention has a good smoothness when applied to an object, has a large adhesive force even for an object such as a plastic foam, and maximizes the purpose of surface protection. It is an object of the present invention to provide a two-component solventless urethane-based resin coating material that can achieve the above.

[0010]

Means for Solving the Problems The two-component solventless urethane resin coating material of the present invention comprises a polyisocyanate component (A),
A two-component solventless urethane resin coating agent comprising a polyol component (B), a cross-linking agent (C) and a catalyst (D), wherein the amount of the polyol component (B) in excess of 50% by weight is the first grade. It is characterized in that it is composed of an OH group-containing polyol and that the cross-linking agent (C) is diethyltoluenediamine. In this case, it is particularly preferable to use a bismuth compound as the catalyst (D).

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The two-component solventless urethane resin coating material of the present invention comprises a polyisocyanate component (A) and a polyol component (B).
The crosslinking agent (C) and the catalyst (D) are essential components.

<Polyisocyanate Component (A)> As the polyisocyanate component (A), various polyisocyanates used in the production of polyurethane can be used, but those mainly composed of diphenylmethane diisocyanate type polyisocyanate are particularly preferable. It is suitable.

Examples of the diphenylmethane diisocyanate type polyisocyanate include (1) diphenylmethane-4,4'-diisocyanate referred to as pure MDI, (2)
Polymethylene polyphenyl polyisocyanate referred to as crude MDI or polymeric MDI, (3) Dicyclohexylmethane-4,4′-diisocyanate referred to as hydrogenated MDI or H ₁₂ MDI, (4) Above (1) to
(3) Polyisocyanate and a modified product of one or more kinds of carbodiimide, isocyanurate, uretonimine, etc., (5) MDI polyisocyanate of (1) to (3) above, and biuret, alohanate, etc. A modified product of one or more kinds, (6) a prepolymer of the polyisocyanate of the above (1) to (3) and a hydroxypolyol (polyalkylene glycol, etc.) or a polyhydric alcohol,
(7) Polyisocyanates of the above (1) to (3), which are modified with carbodiimide, isocyanurate, uretonimine and the like and are prepolymerized with hydroxypolyol or polyhydric alcohol. Among these, (1), (4), (6) and (7), especially (4), (6) and (7) are important.

As polyisocyanates other than diphenylmethane diisocyanate type polyisocyanate,
2,4- or / and 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate,
Isophorone diisocyanate, p-phenylene diisocyanate, transcyclohexane-1,4-diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, tetramethyl xylene diisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate -4-isocyanate Methyl octane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate and the like can be mentioned. However, even when these are used, a small proportion (50 wt% or less, usually 30 wt% or less, further 20 wt% or less) is used in combination with diphenylmethane diisocyanate-based polyisocyanate.
It is desirable to use

<Polyol component (B)> Polyol component
As (B), in the present invention, 50% by weight thereof
The amount exceeding the above (preferably 60% by weight or more, more preferably 70% by weight or more, especially 80% by weight or more) is constituted by the primary OH group-containing polyol. The use of the primary OH group-containing polyol has a positive effect in terms of moderate strength and flexibility (elongation, etc.) of the coating when applied to the surface of an object, adjustment of curing time, and realization of surface smoothness. is there.

The above-mentioned primary OH group-containing polyol has a weight ratio of a high OH value polyol having an OH value X of more than 100 and a low OH value polyol having an OH value smaller than X: 6: 6. It is preferably a mixture of 4-9: 1. This is because a flexible and tough coating can be obtained in such a range. The above OH value X
Is preferably 110 or more, more preferably 115 or more. The upper limit of the OH value X is practically up to about 140.

OH group-containing polyols include primary OH group-containing polyols and secondary OH group-containing polyols.

As the primary OH group-containing polyol in the polyol component (B), polymer polyols and low-molecular polyols exemplified below are used, and polymer polyols are preferably used in a main proportion.

First, as the polymer polyol, polyethylene glycol, polytetramethylene glycol, a copolymer of ethylene oxide and tetrahydrofuran, a polyester polyol such as a condensation type polyester polyol / lactone type polyester polyol / polycarbonate diol is used as a chain extender. Examples thereof include those using a polyol containing only primary OH groups and polybutadiene polyol. Further, polypropylene glycol or polybutylene glycol having a secondary OH group capped with ethylene oxide (that is, an ethylene oxide end block copolymer) can also be preferably used.

The low molecular weight polyols include ethylene glycol, diethylene glycol, triethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4. -Bis (2'-
(Hydroxyethoxy) benzene, trimethylolpropane, pentaerythritol, diethanolamine, triethanolamine, phenyldiethanolamine, N,
Examples thereof include N'-di (2-hydroxyethyl) aniline.

As the secondary OH group-containing polyol, polymer polyols and low molecular weight polyols exemplified below are used.

First, as the polymer polyol, polypropylene glycol, polybutylene glycol, castor oil or a derivative thereof, a random or block copolymer of propylene oxide and butylene oxide, a random or propylene oxide end block of propylene oxide and ethylene oxide. Copolymer, random or butylene oxide end block copolymer of butylene oxide and ethylene oxide, random or propylene oxide end copolymer of propylene oxide and tetrahydrofuran, random or butylene oxide end copolymer of butylene oxide and tetrahydrofuran Obtained by addition-polymerizing propylene oxide to a chain extender such as glycerin or trimethylolpropane Polymers obtained by addition polymerization of butylene oxide to chain extenders such as glycerin and trimethylolpropane, polymers obtained by addition polymerization of propylene oxide and butylene oxide to chain extenders such as glycerin and trimethylolpropane, First-class O
Examples thereof include polymers obtained by addition-polymerizing propylene oxide to H-group-containing polyols and polymers obtained by addition-polymerizing butylene oxide to primary OH-group-containing polyols described above.

The low molecular weight polyols include propylene glycol, dipropylene glycol, tripropylene glycol, 2,4-pentanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,3. 2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 2-ethyl-1,3-hexanediol, glycerin, diglycerin, 1,2,6-hexanetriol,
Examples thereof include sorbitol, triisopropanolamine, phenyldiisopropanolamine, N, N'-bis (2-hydroxypropyl) aniline and the like.

The overall OH value of the polyol component (B) is 10 to
It is preferably in the range of 380 KOHmg / g, especially 20-350 KOHmg / g. This is because when the OH value is in such a range, the physical properties as a coating material are enhanced.

<Crosslinking Agent (C)> In the present invention, diethyltoluenediamine is used as the crosslinking agent (C). Diethyltoluenediamine is a compound represented by the following chemical formula 1.

[0027]

Embedded image

Thus, in the present invention, diethyltoluenediamine is used as the cross-linking agent (C), and the intended purpose can be achieved by this, but an amount (for example, 30% by weight or less, which does not impair the gist of the present invention, (Especially less than 20% by weight)
If so, amines other than diethyltoluenediamine may be used in combination.

<Catalyst (D)> As the catalyst (D), it is particularly preferable to use a bismuth compound in the present invention.
Specific examples of bismuth compounds include bismuth acetate, bismuth oxalate, bismuth oleate, bismuth valerate, bismuth stannate, bismuth citrate, bismuth salicylate, bismuth-2-ethylhexanoate, bismuth neodecanoate, and the like. Organic acid salts, bismuth carbonate, bismuth hydrate,
Examples thereof include bismuth nitrate, bismuth oxide, and bismuth phosphate, and bismuth neodecanoate is particularly important. The bismuth compound is usually used in the form of a solution mixed with an appropriate amount of an organic acid (for example, neodecanoic acid) or the like in a liquid state or in a form of being dissolved in a polyol as a simple substance in order to make it into a liquid state.

As the catalyst (D), catalysts other than bismuth compounds such as tertiary amines, organic tin compounds and organic lead compounds can be used. However, since the effect of the bismuth-based compound is remarkably large as compared with the case where dibutyltin dilaurate is used, for example, the bismuth-based compound is used in an amount of 0.001 with respect to the entire polyol component (B) as described below even when other catalysts are used. It is preferable to use the catalyst in an amount of not less than 0.01% by weight (in particular, not less than 0.01% by weight), and to additionally use another catalyst.

<Other Compounds> The coating material of the present invention includes
In addition to the polyisocyanate component (A), the polyol component (B), the cross-linking agent (C) and the catalyst (D) described above, it is possible to add a chain extender (polyvalent amine etc.) that does not belong to the polyol component. it can. The chain extender belonging to the polyol component is classified as the above-mentioned polyol component (B) for convenience.

In addition, if necessary, a filler, a coloring agent,
A plasticizer, an oxidation stabilizer, an ultraviolet absorber, a flame retardant, an antistatic agent, a hydrolysis inhibitor, an antifungal agent, a dehydrating agent, an antifoaming agent and the like can be added.

<Coating Method> The two-component solventless urethane resin coating agent of the present invention comprises a polyisocyanate component (A)
Agent, polyol component (B) as agent B, crosslinker (C)
The catalyst (D) and the chain extender are usually blended on the side of the B agent.

The mixing ratio of the polyisocyanate component (A) and the polyol component (B) is such that the equivalent ratio of NCO / active H is
It is suitable to set 0.9 to 1.3, preferably 1.0 to 1.2. Active H means H that can react with an NCO group,
For example, H of OH group, H of NH ₂ group, H of COOH group
And so on.

The amount of the cross-linking agent (C) compounded is the polyol component.
(B) 1-40% by weight, preferably 5-30, relative to the whole
It is appropriate to set the content by weight%, and if the proportion is too small, the curing rate, smoothness, and adhesiveness will be unsatisfactory and the coating strength will tend to be lowered, while the proportion will be too large. In this case, the smoothness and the adhesiveness may be deteriorated.

Taking the case of a bismuth compound as an example, the blending amount of the catalyst (D) is based on the entire polyol component (B).
It is suitable to set 0.001 to 10% by weight, preferably 0.01 to 5% by weight, and when the ratio is too small, it becomes unsatisfactory in terms of curing rate, smoothness, adhesion and coating strength,
When the ratio is too large, the smoothness and the adhesiveness may be deteriorated.

The two-component solventless urethane-based resin coating material of the present invention is used by mixing the liquids A and B immediately before use, or
The liquid and the liquid B are mixed and used at the tip of a two-headed gun, and applied to the surface of the object by a method such as coating, dipping or spraying to form a film. As a result, the surface of the object is protected. There is no particular limitation on the thickness of the coating, and any thickness from a thin film to a thick film can be used.

Examples of the object include plastic foam, plastic molded product, metal, wood material, cloth, concrete, inorganic board, and the like, and can be applied to semi-finished products such as shoe soles.

<Function> The smoothness of the film formed when the two-component solventless urethane resin coating material of the present invention is applied to an object is determined by the use of the diethyltoluenediamine used as the crosslinking agent (C) and the catalyst ( D) (particularly bismuth-based compound) is deeply involved, and if either one is omitted, shrinkage or unevenness may appear, or smoothness may be impaired. Even if diethyltoluenediamine is used as the cross-linking agent (C),
When a catalyst other than a bismuth-based compound is used as the catalyst (D), a crosslinking agent similar to that when a bismuth-based compound is used.
Since a synergistic effect with (C) cannot be achieved, it is particularly recommended to use a bismuth-based compound as the catalyst (D).

The combination of diethyltoluenediamine used as the cross-linking agent (C) and the catalyst (D) (particularly bismuth compound) is extremely advantageous in terms of adhesion to an object (particularly plastic foam). Act on. This is an anchor effect based on the appropriate cohesive action of the above-mentioned cross-linking agent (C),
This is probably because the curing rate with the catalyst (D) (particularly bismuth-based compound) cooperated.

[0041] The desired film strength and flexibility (elongation, etc.) can be obtained by combining the components of the composition of the present invention together in appropriate amounts, and the smoothness when applied to an object can be obtained. The property is good, and even an object such as a plastics foam has a large adhesive force, and the object of surface protection can be achieved to the maximum extent.

[0042]

The present invention will be further described with reference to the following examples. Hereinafter, "parts" refers to parts by weight.

Example 1 <Liquid A> 61 parts of carbodiimide-modified diphenylmethane-4,4'-diisocyanate having a free NCO% of 29.0 was prepolymerized with 39 parts of polypropylene glycol having a molecular weight of 2000 at a temperature of 80 ° C. in a nitrogen stream. The reaction was carried out for 2.0 hours to obtain a prepolymer having a free NCO% of 16.4.
This was used as the polyisocyanate component (A).

<Liquid B> As the polyol component (B), the molecular weight obtained by addition polymerization of polypropylene glycol with ethylene oxide is 900, and the OH value is 125 mgKOH /
g of primary OH group-containing polyol (polymer polyol)
67 parts, 14 parts of a primary OH group-containing polyol (polymeric polyol) having a molecular weight of 4000 obtained by addition-polymerizing ethylene oxide to polypropylene glycol and having an OH value of 28 mgKOH / g and a 1,4-butanediol (chain) Mixture with 6 parts of low molecular weight polyol that also serves as extender, cross-linking agent
13 parts of diethyltoluenediamine as (C), and 1.0 part of a solution of bismuth neodecanoate as a catalyst (D) in neodecanoic acid (the proportion of bismuth is 16% by weight) were mixed to prepare a liquid B.

<Formation of coating> Using a spray device "QSP-26" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., a mixture of the above liquids A and B (NCO) was applied to a flat plate made of a polystyrene foam having an expansion ratio of 70 times. The equivalent ratio of / active H was 1.1) and the coating was formed. Similarly, a film was formed on the polypropylene plate.

The surface of this fully cured product has appropriate flexibility, is rich in impact resilience, and is tough, not to mention damage to the coating film due to impact from the outside as well as damage to the foam in the case of foam. Was not recognized. The film-forming surface had good surface smoothness, and the appearance was favorable. Further, the adhesiveness was good, and for example, in the peeling test between the coating film and the foam, cohesive failure of the foam occurred.

Comparative Example 1 When Example 1 was repeated except that the catalyst (D) was not blended, curing of the coating was not sufficiently accelerated and creaming occurred.

Comparative Example 2 Example 1 was repeated except that 13 parts of 4,4'-diaminodiphenylmethane was used as the crosslinking agent (C) instead of 13 parts of diethyltoluenediamine.

This solution B was mixed with the same solution A as in Example 1 (the equivalent ratio of NCO / active H was 1.1) and sprayed on a polypropylene plate in the same manner as in Example 1 to form a film.

However, the surface of this fully cured product had irregularities and lacked smoothness, and the appearance was poor. Also, the adhesion was poor, and interfacial peeling occurred in the peeling test.

Reference Example 1 49 parts of polypropylene glycol having a molecular weight of 1000 as the polyol component (B) (secondary OH group-containing polyol, high molecular weight polyol) 49 parts, molecular weight of 4,000 polypropylene glycol (secondary OH group containing polyol, high molecular weight polymer) A mixture of 32 parts of polyol) and 6 parts of 1,4-butanediol (a low molecular weight polyol which also serves as a chain extender), 13 parts of diethyltoluenediamine as a crosslinking agent (C), and bismuth neodeca as a catalyst (D). 1.0 part of a solution of noate in neodecanoic acid (the proportion of bismuth was 16% by weight) was mixed to prepare a solution B.

This solution B was mixed with the same solution A as in Example 1 (NCO / active H equivalent ratio was 1.1) and sprayed on a polypropylene plate in the same manner as in Example 1 to form a film.
The results are shown in Table 1 below.

The surface of this fully cured product was good, but it lacked in flexibility and was harder than that of Example 1. Further, as shown in Table 1, the hardness was larger and the elongation was smaller than that of Example 1. Therefore, when flexibility is required, the example 1 is preferable to the reference example 1.

Reference Example 2 Polypropylene glycol having a molecular weight of 1000 as a polyol component (B) (secondary OH group-containing polyol, polymer polyol) 33 parts, molecular weight 2,000 polypropylene glycol (secondary OH group-containing polyol, polymer) A mixture of 48 parts of polyol) and 6 parts of 1,4-butanediol (a low molecular weight polyol which also serves as a chain extender), 13 parts of diethyltoluenediamine as a crosslinking agent (C), and bismuth neodeca as a catalyst (D). 1.0 part of a solution of noate in neodecanoic acid (the proportion of bismuth was 16% by weight) was mixed to prepare a solution B.

This solution B was mixed with the same solution A as in Example 1 (the equivalent ratio of NCO / active H was 1.1) and sprayed on a polypropylene plate in the same manner as in Example 1 to form a film.
The results are shown in Table 1 below.

The surface of this fully cured product was good, but it lacked in flexibility and was harder than that of Example 1. Further, as shown in Table 1, the hardness was larger and the elongation was smaller than that of Example 1. Therefore, when flexibility is required, the example 1 is preferable to the reference example 2.

Example 2 61 parts of carbodiimide-modified diphenylmethane-4,4'-diisocyanate having a free NCO% of 29.0 was mixed with a polyoxypropylene polyoxyethylene block copolymer having a molecular weight of 2400 at a temperature of 80 ° C. in a nitrogen stream (terminal poly (Oxyethylene) 39 parts was prepolymerized and reacted for 2.0 hours to obtain a prepolymer having a free NCO% of 16.4.
This was used as the polyisocyanate component (A).

This solution A was mixed with the same solution B as in Example 1 (the equivalent ratio of NCO / active H was 1.1) and sprayed on the polystyrene foam in the same manner as in Example 1 to form a film.

The surface of this fully cured product has appropriate flexibility, is rich in impact resilience, and is tough, not to mention damage to the coating film due to impact from the outside as well as damage to the foam in the case of foam. Was not recognized. The film-forming surface had good surface smoothness, and the appearance was favorable. Further, the adhesiveness was good, and for example, in the peeling test between the coating film and the foam, cohesive failure of the foam occurred.

Example 3 60 parts of carbodiimide-modified diphenylmethane-4,4'-diisocyanate having a free NCO% of 29.0 was prepolymerized with 40 parts of polypropylene glycol having a molecular weight of 3000 at a temperature of 80 ° C. in a nitrogen stream for 2.0 hours. The reaction was performed to obtain a prepolymer having a free NCO% of 16.5. This was used as the polyisocyanate component (A).

This solution A was mixed with the same solution B as in Example 1 (NCO / active H equivalent ratio was 1.1), and sprayed on the polystyrene foam in the same manner as in Example 1 to form a film.

The surface of this fully cured product has appropriate flexibility, is rich in impact resilience, and is tough, not to mention damage to the coating film due to impact from the outside, as well as damage to the foam in the case of foam. Was not recognized. The film-forming surface had good surface smoothness, and the appearance was favorable. Further, the adhesiveness was good, and for example, in the peeling test between the coating film and the foam, cohesive failure of the foam occurred.

<Various Test Results> In order to carry out a quantitative evaluation, the coating solutions of Examples 1 to 3, Comparative Example 3 and Reference Examples 1 and 2 were used, and the above solutions A and B were applied to polypropylene plates. Sprayed a mixture of (NCO / active H equivalent ratio of 1.1)
A film was formed. Similarly, it was sprayed on a polystyrene foam flat plate having an expansion ratio of 70 times and sufficiently cured, and then the appearance of the coating and the adhesion between the coating and the foam were examined.
It was evaluated as (good) or x (bad). Table 1 shows the test results of hardness (JIS-A), tensile strength, tensile elongation, and tear strength at this time. Comparative Example 1 was not listed in Table 1 because the hardening of the coating did not proceed sufficiently and creaming occurred.

[0064]

[Table 1] Implementation Examples Comparative Example Reference Example 1 2 3 2 1 2 Hardness (JIS-A) 80 85 80 98 90 97 Tensile strength ^{(kgf / cm 2) 120 110} 120 210 130 180 Tensile elongation (%) 560 600 570 100 320 200 Tear strength (kgf / cm ² ) 40 40 35 30 40 45 Appearance ○ ○ ○ × ○ ○ Adhesion ○ ○ ○ × ○ ○

Example 4 As the polyol component (B), a primary OH group-containing polyol (polymer polyol) having a molecular weight of 900 and an OH value of 125 mgKOH / g obtained by addition polymerization of polypropylene glycol with ethylene oxide 57 parts, 24 parts of a primary OH group-containing polyol (polymer polyol) having a molecular weight of 1670 and an OH value of 67 mgKOH / g obtained by addition-polymerizing ethylene oxide to polypropylene glycol, and 1,4-butanediol (chain) Mixture with 6 parts of a low molecular weight polyol that also serves as an extender, 13 parts of diethyltoluenediamine as a cross-linking agent (C), and a neodecanoic acid solution of bismuth neodecanoate as a catalyst (D) (the proportion of bismuth is 16% by weight). %) 1.0 part was mixed to prepare a liquid B.

This solution B was mixed with the same solution A as in Example 1 (the equivalent ratio of NCO / active H was 1.1) and sprayed on a polypropylene plate in the same manner as in Example 1 to form a film.
The surface of this fully cured product has moderate flexibility, is rich in impact resilience, is tough, and not only damage to the coating due to external impact, but also damage to the foam is observed even in the case of foam. There wasn't. The film-forming surface had good surface smoothness, and the appearance was favorable. Further, the adhesiveness was good, and for example, in the peeling test between the coating film and the foam, cohesive failure of the foam occurred.

In the same evaluation as in Table 1, the hardness (JISI
-A) is 83, tensile strength is 125 kgf / cm ² , tensile elongation is 5
The tear strength was 80%, the tear strength was 38 kgf / cm ² , the appearance was ◯, and the adhesion was ◯.

[0068]

EFFECTS OF THE INVENTION By using the two-component solventless urethane resin coating material of the present invention, not only the desired coating strength and flexibility (elongation etc.) but also the smoothness when applied to an object can be obtained. It is good, and even an object such as a plastic foam has a high adhesion, and the object of surface protection can be maximally achieved.

Claims (6)

[Claims] 1. A two-component solventless urethane resin coating agent comprising a polyisocyanate component (A), a polyol component (B), a cross-linking agent (C) and a catalyst (D), wherein the polyol component (B) A two-component solventless urethane-based resin coating material characterized in that an amount exceeding 50% by weight is composed of a primary OH group-containing polyol, and the crosslinking agent (C) is diethyltoluenediamine. . 2. A primary OH group-containing polyol is a high OH value polyol having an OH value X exceeding 100 and an O value.
The two-component solventless urethane resin coating material according to claim 1, which is a mixture having a weight ratio of 6: 4 to 9: 1 with a low OH polyol having an H value smaller than X. 3. The two-component solventless urethane resin coating material according to claim 2, which has an OH value X of 110 or more. 4. The two-component solventless urethane resin coating material according to claim 1, wherein the catalyst (D) is composed of a bismuth compound. 5. The two-component solventless urethane resin coating material according to claim 1, wherein the polyisocyanate component (A) is mainly composed of diphenylmethane diisocyanate polyisocyanate. 6. A coating agent for protecting the surface of an object.
The two-component solventless urethane resin coating material described.