JPS60147448A - Polyurethane resin composition for dry expansion - Google Patents

Abstract

PURPOSE:To provide the titled composition capable of giving highly heat- and solvent-resistant expanded surface free from stickiness and yielding phenomena, comprising terminal isocyanate group-blocked urethane prepolymer, polyamine- based corsslinking agent, heat-decomposable foaming agent and solvent. CONSTITUTION:The objective composition can be obtained by incorporating (A) a solution of blocked urethane prepolymer which is prepared from (i) a polyol with a molecular weight 400-4,000 and (ii) polyisocyanate followed by blocking the resultant terminal isocyanate group by e.g. methylethyl hetone oxime with (B) a crosslinking agent such as iminobispropylamine, (C) heat-decomposable foaming agent such as diazobenzene with its decomposition point similar to the dissociation temperature of the component (A), pref. the difference between them being smaller than 20 deg.C, and, optionally, (D) foam stabilizer, pref. filler, etc. Said composition is coated on a base, being expanded while distilling off the solvent contained to form a crosslinked expanded layer. The amount of said foaming agent to be used is 2-20(pref. 4-15)pts.wt. per 100pts.wt. of the polyurethane resin.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a polyurethane resin composition that can be formed into a foam by a dry process. The present invention relates to a polyurethane resin composition for dry foaming, which comprises a crosslinking agent comprising a compound of the same type, a thermally decomposable foaming agent JjJ, and a solvent. - This composition produces a crosslinked foam layer by applying it onto a substrate and foaming it while distilling off the solvent.

Conventionally, the method for producing a foam layer using polyurethane resin has been to prepare a film or sheet by preparing a mixture of a polyurethane resin solution with a hydroxyl group at the end, a polyisocyanate compound, and an organic blowing agent. ,
1. A method of proceeding with crosslinking reaction by heat treatment to form a thermosetting polyurethane resin foam layer (Japanese Unexamined Patent Publication No.
No. 48-25066), ■ A fine powder foaming agent made of bicarbonate such as bicarbonate/ammonium acid or sodium bicarbonate is mixed with a polyurethane resin solution, and after application, the foaming agent is decomposed and the foaming agent is decomposed. Method of forming a foam layer (
JP-A No. 52-90604), ■ A method of adding water to an isocyanate-terminated prepolymer and coating it to form a foam layer (JP-A No. 56-107081), □■' Using a polyurethane resin solution A W10 type emulsion was produced, this emulsion was applied onto a substrate, the solvent in the emulsion was evaporated, and then the water was evaporated.
Therefore, there is a method of forming a foamed layer consisting of fine pores from which the solvent has been distilled off. ' These conventional methods are unique in forming a foamed/foamed layer, but when they are carried out, operational problems and product defects have also been pointed out.

For example, in method (2), the mixture is first formed into a film or sheet, pre-dried at 80°C for 30 minutes to distill off the solvent, and then heated to a temperature of 160-220°C, which is above the thermal decomposition temperature of the blowing agent. Two culms are required for drying by heating for 2 to 5 minutes at a high temperature of °C. In addition, due to the reaction between the terminal hydroxyl group and isocyanate, it takes a long time to crosslink, and when mass production is carried out industrially,
It is difficult to obtain a uniform foam layer due to sagging of the foam layer during winding of the final roll after the culm.

In method (2), when ammonium bicarbonate is used, ammonia gas is generated during the work, which is not only undesirable for the needle bed of the worker, but also when bicarbonate is used, the foamed cells of the final product are rough and foamed. A8 ratio: t) is low and is far from a preferable foam, so this method is hardly used as an industrial manufacturing method.

In method (2), the bot rhino of liquid II is λ(j), and the viscosity of the liquid changes over time, making it difficult to apply uniformly and making work management very difficult.

In method (2), the stability of the W10 emulsion is short, a skin phenomenon is observed on the liquid surface, constant stirring is required, and
A streaking phenomenon is also observed in the poem, making it difficult to generate a uniform foam layer. Furthermore, in order to avoid crushing the foam layer,
Drying requires a long time at low temperatures, which poses problems in terms of workability when industrially mass-producing.

In contrast, the composition of the present invention greatly improves the drawbacks of the conventional compositions described above when used as a foam layer.

A detailed explanation of this invention follows.

The polyurethane resin used in this invention has a terminal isocyanate group blocked with a blocking agent, so the solution is stable, and a resin solution with a pot life is used for management or work reasons. A crosslinking reaction occurs simultaneously with the dissociation of the blocking agent by heating to form a crosslinked film, so that there is no surface adhesion or sagging during direct foaming, and a good surface with good heat resistance and solvent resistance is created.

In addition, in this invention, the blowing agent is preferably one whose temperature difference is within 20°C, for example, an isocyanate which is 10-blocked with an oxime, since its decomposition YnA lu is similar to the dissociation mIO of a blocked isocyanate. Although the dissociated warm melon of the block body is about 130 to 140°C, by using azosicabonamide in which the decomposed moisture is lowered to 140°C as a urea compound, it cannot be visually identified. In addition, a foam having uniformly dispersed foam cells is formed, and the surface is smooth and the appearance is excellent. Its appearance is as good as that of the microporous film produced by the wet process, which is considered the best conventional foam.

The polyurethane resin composition for wet foaming of the present invention can be used to create various foamed films with different expansion ratios by arbitrarily using the resin composition, foaming agent, and other additives. When used as a base material for synthetic leather, it not only makes it possible to produce a wide variety of types of synthetic leather, but also makes it possible to produce synthetic leather that is almost the same as wet-processed synthetic leather, which is considered to be the best in the past. It is. Furthermore, even though it is a cross-linked type, it has very significant effects such as significantly improved stability and workability compared to conventional two-component types and types using blocked isocyanate.

The urethane prepolymer having a terminal isocyanate-1 group used in the present invention may be a polyol having a molecular weight of 400 to 4,000 such as a polyester polyol, a polyether polyol, a polycarb, or a rolactone polyol, either singly or as a mixture. Bolier, ster polyol, ethylene glycol, butylene glycol
', hexylene glycol, diethylene glycol,
Polyols such as dipropylene glycol and neopentyl glycol, and polycarboxylic acids such as succinic acid, geltaric acid, adipic acid, cepatic acid, maleic acid, fumaric acid, and trimellitic acid, so that the terminal end is a hydroxyl group. It is given in response.

Polyether polyols include polyj tramethylene glycol, polypropylene glycol, polyethylene glycol, glycerin propylene oni A-le et al. Polycaprolactone polyols have also been used in history.

These polyols may be used alone or in combination. Furthermore, -C low molecular weight CD glycol may be used if necessary.

Next, the right I isographs used in this invention are shown below.
Examples include 2,4- and 2,6-toluylene diisocyanate, 4,4'-diphenylmethane diisocyanate)
1,5-naphthylene diisocyanate, xylylene diisocyanate, 1,6-hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 3-yne Methyl cyanate-3,! There are aliphatic polyisocyanates such as +,5'-trimethylcyclohexyl isocyanate and 2,6-dicyanatomethyl caproate, which can be used alone or in combination.

A prepolymer having a terminal isocyanate group using a polyol and a polyisocyanate may be produced by a conventionally known method. For example, there is a method in which a system in which the number of moles of isocyanate groups is in excess of hydroxyl groups is heated under a nitrogen stream and stirred. In this case, reaction control additives, reaction accelerating additives,
The reaction may be carried out by adding an inert solvent or an antioxidant to the urethanization reaction using dimethylformamide (DMF), methyl ethyl ketone (MEK), t-toluene, or the like. The isocyanate-terminated prepolymer thus obtained can be treated with conventionally known blocking agents, such as phenol, phenol derivatives such as cresol, xylenol, and chlorophenol, acetoacetate, diethyl malonate, acef)I, acetate, etc. . □V eye. , Kaa. Blocking is performed using oximes such as 5'cutam and acetoxime to obtain a blocked isocyanate.

The blocked isocyanate is heated to form an isocyanate group, and a polyalkylene polyamine may be used as a compound having an active hydrogen that reacts with the isocyanate, for example, iminobispropylamine, diethylenetriamine, etc. t capable of reacting with isocyanate groups;'i 1! It is desirable to have three or more amino groups having the following formula. Furthermore, a conventionally known catalyst may be used if necessary.

Further, the blowing agents used in this invention include Schiff/zobenzene, diazoaminobenzene, )lzobisisobutylnitrile, azohexahytobenzonyl-1-lyl, benzenesulfonylhydrazide, l'), p'-oxy Bisbenzenesulfonylhydrazide, dinitropentamethylenetetramine, N,N'-dimethyl-N,N'-dinitrointerephthalamide, a,,zodicarbamide, P,P'-oxybisbenzenesulfonyl semicarbamide, MIA M>'Midoguanidine, P, P'-thiobisbenzenesulfonyl hydrazide, P, P'-diphenylmethanesulfonyl hydrazide, benzene-disulfonyl hydrazide, terephthazide benzazide, p
-t-butylbenzasite, phthalazide, isophthalazide,
Examples include 1,3-diphenyltriazine and diethyl azodicarboxylate, and these may be used alone or in combination. Furthermore, these blowing agents and urea compounds,
The thermal decomposition temperature can also be adjusted by using an organic acid catalyst. If the amount of the foaming agent used is less than 2 parts by weight, the foaming ratio will be so low that foaming will hardly be observed, making it impossible to obtain the foam that is the object of the present invention. If it exceeds 20 m 1 part, the foaming ratio becomes high, the surface of the foam becomes rough, the surface smoothness is lost, and the toughness of the foamed film is also lost. If the foaming ratio is extremely high, it will be easily destroyed by friction or the like. Therefore, the amount of these blowing agents used is 2 to 20 m 1 part per 100 wt ω parts of the polyurethane resin,
It is preferably 4 to 15 parts by weight.

In addition, if necessary, foam stabilizers, fillers, colorants, stabilizers, plasticizers, pigments, etc. used in conventional polyurethane resin manufacturing techniques can be added to the polyurethane resin composition. It has a great effect of making the foam cells more dense and uniform, smoothing the surface of the foam, and improving its strength. As such fillers, inorganic fillers such as silica and calcium carbonate, and 1.1-organic fillers such as microscopic cellulose are preferable, and these can be used alone or in combination. .

The present invention will be explained in detail below with reference to Examples. All parts in the Examples are parts by weight.

Example 1 Average molecule ri1 with 4'ii hydroxyl groups at both ends
1000 polyethylene butylene adibe 1-1000
45 parts of 1,4-butanediol, and 630 parts of dimethylformamide were dissolved under a nitrogen stream, and 4,41-diphenylmethane diisocyanate-1-
Add 200 parts of
- Add 209 parts of lylene di incyanate (2,4-12,6-different ratio of 80:20) to 100
After holding at 1 hour at 1 hour to remove the isocyanate-terminated prepolymer, the prepolymer was cooled to 60 0 C, and 10 parts of methyl ethyl ketone oxime was gradually added. The thus obtained blocked urethane prepolymer has a solid content of 10% and a viscosity of 15,000 at 25°C.
It was centipoise.

Blocked urethane prepolymer solution 10 obtained next
Add 2 parts of iminobispropylamine as a crosslinking agent, 5 parts of Azocicabonamide (AZC) with a thermal decomposition temperature of 140°C as a foaming agent, and 1 part of foam-regulating silicone (manufactured by Shin-Etsu Chemical Co., Ltd.) as a foam stabilizer to 0 parts, and mix well. A foamed polyurethane resin composition was obtained by stirring.

First, as a skin layer on release paper DN-TP-AP-M (manufactured by Dainippon Printing), u-2'z1e<manufactured by Seiko Kasei) 2
The foamed polyurethane resin composition obtained in Example 1 was applied to a 0% solution and dried to a thickness of 0.20 mm, and heated at 140°C for 2 minutes, resulting in the results shown in Table 1 below. We were able to obtain a foamed layer. r1st table foaming agent Main component AZC Foaming agent thermal decomposition temperature ('C) 140 Expansion ratio 4 Thinness of foamed cells 0 Smooth marks on foamed surface O As a result, the foamed layer expanded and expanded to a thickness of 0.60 mm I was able to get

By applying an adhesive layer to this foam layer and pasting it with a fabric, a synthetic leather with excellent flexibility and thickness, heat resistance V1, and chemical resistance was obtained, which was suitable for use in bags, bags, etc.

Example 2, average molecular weight 100 with hydroxyl groups at both ends
0 polyethylene butylene atsube-1-1000 parts, 1
．． 45 parts of 4-butanediol and 630 parts of dimethylformamide were dissolved in a nitrogen stream, and 4°4'
-200 parts of diphenylmethane diisocyanate was added and kept at 80°C for 0.5 hours, and further l-lylene diisocyanate-1 to (2,4-12,6-
20) was added and held at 100°C for 1 hour to obtain an isocyanate-terminated prepolymer. After that, it was cooled to 6'0℃, and methyl ethyl ketone oxime 70
Gradually add 100% of
A centiboise/25° C. blocked urethane prepolymer was obtained.

Blocked urethane prepolymer solution 10 obtained next
0 parts, 2 parts of iminobispropylamine as a crosslinking agent, and 5 parts of a blowing agent.
N>, ■P-toluenesulfonyl hydrazide (1-38
) were used.

Additionally, add 7 parts of foam regulating silicone F-1'14 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a foam stabilizer and 2.5 parts of finely powdered crystalline cellulose W-300 (manufactured by Dezumi Kokusaku Pulp Co., Ltd.) as a filler, and stir well. A foaming polyurethane resin composition was obtained.・ Then, a 20% solution of Ll-2216 (Seiko Kasei) was applied as a skin layer on release paper DN-T'P-AP-M (manufactured by Dainippon Printing), dried, and then the paper was coated. 1ξ
The foaming polyurethane resin composition of the octopus example was applied to a thickness of 0.20 mm and heated at 140° C. for 2 minutes, resulting in a foamed layer as shown in Table 2 below.

Table 2 (Note) The evaluation in the above table is 01o... No problem in practical use Δ... There is a risk of causing problems in practice ×, ××・
... made it impractical.

As a result of the above table, it was possible to obtain a foam layer with a thickness of 0.60 mm in the case of ■■, but the degree of expansion was somewhat low in the case of ■. In addition, in case of +3, the surface of the foam layer was not smooth and rough surface was observed.When an adhesive layer was applied to the foam layer obtained in case of 0■ and the base fabric was attached, flexibility and Synthetic leather was obtained that was thick, had excellent heat resistance, chemical resistance, and abrasion resistance, and had a better texture than that obtained in Example 1, and was suitable for making bags, bags, etc. .

Example 3 1000 parts of polyethylene adipate having an average molecular weight of 1000 and having hydroxyl groups at both ends, 45 parts a3 of 1,4-butanediol, and 630 parts dimethylformamide were dissolved in a nitrogen stream, and 4,4'-diphenylmethane diol was dissolved therein. Add 200 parts of isocyanate-1 to 80 parts
The mixture was kept at 100 DEG C. for 0.5 hour, 300 parts of 4.4'-diphenylmethane diincyanate was added, and the mixture was kept at 100 DEG C. for 1 hour to obtain an isocyanate-terminated prepolymer. 1
Thereafter, it was cooled to 60°C, and 10 parts of methyl ethyl ketone oxime was gradually added to make the solid content concentration 70% at 125°C.
A blocked urethane prepolymer having a viscosity of 10,000 centivoice was obtained.

Next, 100 parts of this blocked urethane prepolymer was mixed with 2 parts of iminobispropylamine as a crosslinking agent, and 4,4.A.tosibisbenzenesulfonyl hydrazide CO'BS with a thermal decomposition temperature of 150°C as a foaming agent. +1) 5 parts,
1 part of foam regulating silicone 1lm-114N (manufactured by Etsu Kagaku) as a foam stabilizer, 5 parts of silica with an average particle size of 3.5μ as a filler
y-244 (manufactured by Fuji Davison Chemical) '2.5 parts were added and mixed well to obtain a foamed polyurethane IM resin composition.

ml of this foamed polyurethane resin composition 1) N-
TP-NM (manufactured by Dainippon Printing) with a thickness of 0.15ml1
1 and heated at 140°C for 2 minutes, the result was a thick, strong foam with uniformly dispersed foam that was not visually discernible and had excellent heat resistance and chemical resistance. Sa0.3
One inch of foamed film expanded to 5 mm was able to be removed. This was also a foamed membrane with a vibration-absorbing effect suitable for use in the protective packaging of small parts such as precision machinery.

Example 4 Average molecular weight 1000 with hydroxyl groups at both ends
1-iooo parts of polyethylene butylene adipate, 1.
45 parts of 4-butanediol and 630 parts of dimethylformamide were dissolved in a nitrogen stream, and 1.6 parts of
- Added 134 parts of hexamethylene diisocyanate and held at 90°C for 1.0 hour, then added 266 parts of 3-isocyanate methyl-3,5,5'L trimethylcyclohexyl isocyanate and heated at 100°C for 2.0 hours. After holding for 0 hours, the mixture was cooled to 60° C., and 8 parts of anhydrous piperazine was added to obtain an isocyanate-terminated prepolymer. after that,
Furthermore, the blocked urethane prepolymer obtained by gradually adding 70 parts of methyl ethyl ketone oxime has a solid content of 10% and a viscosity of 1 soo at 25°C.
It was osendipoise.

'Next, 1.6 parts of diethylenetriamine was added as a crosslinking agent to 100 parts of this blocked urethane prepolymer, and azocigarbonamide (A
ZC) 5 parts, foam regulating silicone F-114 (
1 part (manufactured by Shin-Etsu Chemical), 1 part light calcium carbonate (made by Shin-Etsu Chemical) as a filler (
2.5 parts (manufactured by Maruo Calcium) were added and stirred well to obtain a foamed polyurethane resin composition.

This foamed polyurethane resin composition was first coated with release paper DN-T.
L as a skin layer on P-AP-M (manufactured by DaiEihon Printing)
A 20% solution of l-2216 (manufactured by Seiko Kasei) was coated and dried to a thickness of 0.20+nm, and heated at 140°C for 2 minutes. As a result, JI, I
1 foam layer expanded to a diameter of 0.55mm! We were able to. By applying an adhesive layer to this and bonding it with a base fabric, we obtained a synthetic leather that is superior in thickness, heat resistance, and 1-f wear resistance, making it suitable for uses such as bags, furniture, and chairs. .

Patent Applicant Seiko Kasei Co., Ltd. Agent Patent Attorney W 1:11 1 Bi 1 Procedure Nei City Authorization (Spontaneous) 1. Indication of the Case Patent Application No. 3329 of 1981 2. Name of the Invention Polyurethane Resin for Dry Foaming Composition 3, relationship to the case of the person making the amendment Patent applicant address: 1109 Ariku, Junwa-cho, Iyoya-cho, Nishi-ku, Kobe Name: Seiko Kasei Co., Ltd. 4 Agent address: 1-18 Nakatsu, Oyodo-ku, Osaka-shi Column r6 of “Detailed Description of the Invention” of Specification No. 18, Contents of Amendment As shown in the attached sheet, Contents of Amendment 1, page 5, line 9 of the specification [cannot be identified visually] The foam cells produced are made up of very small micropores.
I'll start by correcting that.

2.Page 5, line 10 , Delete "has foam cells".

3.Page 5, line 15 Correct "wet" to "dry".

4, page 6, line 18, after "fumaric acid," do not insert phthalic acid, -1.

5. Line 12, negative line 11 [Foam regulating silicone Shin-Etsu Chemical! "Made by R)" has been corrected to "foam-regulating silicone F-114 (manufactured by Shin, Etsu Kagaku ■ Industry 1)".

α　Table 1 on page 13 of the same is corrected as follows.

“Table 1 First, I corrected "Part 7" to "Part 1."

Claims (1)

[Claims] A polyurethane resin composition for dry foaming comprising a urethane prepolymer, a polyamine-based crosslinking agent, a thermally decomposable □-type foaming agent, and a solvent, in which terminal isocyanate groups are blocked.