JPH0631788A - Packaging material manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] A method for manufacturing packaging materials by polyolefin extrusion lamination, which uses a highly versatile and hygienic ink to produce packaging materials with excellent work efficiency, economy, and hygiene. I will provide a. In the method for producing a packaging material in which a printing film for soft packaging is printed with a printing ink for laminating and a polyolefin film is extruded and laminated, the main binder of the laminating ink is a hydrogenated polybutadiene containing a terminal hydroxyl group as a polyol component. A method for producing a packaging material, which is a urethane resin using a polyol.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a packaging material, and more particularly to the production of a packaging material using a printing ink for laminating which is highly versatile and hygienic in the production of a laminated packaging material used for food packaging and the like. Regarding the method.

[0002]

2. Description of the Related Art Polyethylene extrusion laminates (P extrusion laminates (P
EEL) is one in which an anchor coating agent is applied after printing is performed on a printing film for a soft packaging material and polyethylene is extruded and laminated, and an ink having a composition containing a urethane resin or a chlorinated polyolefin resin as a main binder is used. in use. At this time, it is necessary to apply the anchor coating agent, because polyethylene cannot be laminated without the anchor coating agent regardless of the non-printed portion or the printed portion. On the other hand, polypropylene extrusion laminate (P
In case of PEL), after printing on the OPP film,
Polypropylene is directly extruded and laminated without applying an anchor coating agent, and an ink having a composition containing a chlorinated polyolefin resin as a main binder is used.

[0003]

However, a printing ink containing a urethane resin as a main binder exhibits sufficient adhesiveness to nylon films, polyester films, etc., but insufficient adhesiveness to polyolefin films, On the other hand, printing inks containing chlorinated PP as a main binder showed good adhesiveness to polyolefin films, but did not adhere to printable films other than PP-based films and lacked versatility. Therefore, it is necessary to change the printing ink depending on the film to be printed, or by extruding and laminating polyethylene or polypropylene after printing.
This was a cause of a significant drop in efficiency during printing. Also,
The workability was inferior to that of polypropylene extrusion because an anchor agent was always applied when polyethylene was extruded, and in the case of polypropylene extrusion, the film to be printed was limited to OPP. Further, the printing ink containing chlorinated PP or the like as the main binder requires a large amount of toluene as a solvent, and thus is not preferable in terms of hygiene, that is, residual solvent of the packaging material and working environment.

The present invention uses highly versatile printing ink,
The objective is to improve the efficiency of packaging material manufacturing, diversify the combination of printed film and extrusion film, and improve the hygiene of packaging materials.

[0005]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems.

The present invention relates to a method for producing a packaging material in which a printing film for soft packaging material is printed with a printing ink for laminating, and a polyolefin film is extruded and laminated. In the method for producing a packaging material, the main binder of the laminating ink is a terminal hydroxyl group as a polyol component. The present invention relates to a method for producing a packaging material, which is a urethane resin using a hydrogenated polybutadiene polyol contained therein.

The urethane resin, which is the main binder of the printing ink for laminating used in the present invention, is a hydrogenated polybutadiene polyol having a hydroxyl group at the terminal and a molecular weight of 400 to 8,000, or other polymer polyols and organic diisocyanates. Also, it is formed from a chain extender and an end cap agent, if necessary.

The hydrogenated polybutadiene polyol has a hydroxyl group at the terminal and an average molecular weight of 400 to 8,000, preferably 1,000 to 4,000. The average number of functional groups is 1 to 3, preferably 1.6 to 2.0.
This hydrogenated polybutadiene polyol can be obtained by a known method of hydrogenating a polybutadiene polyol using a palladium catalyst or the like. Examples of commercially available hydrogenated polybutadiene polyol having a hydroxyl group at the terminal include “Polytail H” and “Polytail HA” manufactured by Mitsubishi Kasei Co., Ltd.

These hydrogenated polybutadiene polyols can be used in combination with other polymer diols if necessary. As the other polymer diol, those generally used in the production of polyurethane can be used. Specifically, polyester diols such as dicarboxylic acids (adipic acid, azelaic acid, sebacic acid, succinic acid, phthalic acid, isophthalic acid, glutaric acid, maleic acid, fumaric acid, etc.) and glycols (ethylene glycol, propylene glycol, 1 , 4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,8-octamethylenediol, neopentyl glycol, bishydroxymethylcyclohexane, bishydroxyethylbenzene, alkyl dialkanolamine, etc.) Condensation products such as polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyethylene / propylene adipate; polylactone diols by ring-opening polymerization of lactones, such as polycaprolactone All, polyvalerolactone diol, etc., as well as polyether polyols, such as polyether polyols [alkylene oxides of low molecular weight glycols (ethylene glycol, propylene glycol, 1,4-butanediol, etc.) (alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide, Propylene oxide and butylene oxide) adduct and ring-opening polymer of the above alkylene oxide] Specifically, polyethylene glycol, polypropylene glycol and polytetramethylene ether glycol; ethylene oxide of bisphenol A, propylene oxide adduct and two or more kinds of these Examples thereof include a copolymer (copolycondensation) product or a mixture. Of these, polyester diol and polylactone diol are particularly preferable.

The average molecular weight of the polymeric diol (as measured by hydroxyl value) is usually 300 to 10,000, preferably 1,000 to 5,000. The mixing ratio of the high molecular diol is arbitrary, but the ratio of the hydrogenated polybutadiene diol is 30% by weight of the total amount of the high molecular diol.
It is preferably 40% or more.

As the organic diisocyanate, there are already known aliphatic diisocyanates (1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate and low molecular weight glycols such as ethylene glycol and propylene glycol and the above-mentioned fatty acids. Alicyclic diisocyanates (isophorone diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, methylcyclohexylene diisocyanate, etc.)
Isopropylidenedicyclohexyl-4,4'-diisocyanate and prepolymers of low molecular weight glycols and the alicyclic diisocyanate); aromatic diisocyanates (4,4'-diphenylmethane diisocyanate,
Xylylene diisocyanate, tetramethyl xylylene diisocyanate, tolylene diisocyanate, and prepolymers of low molecular weight glycols and the above aromatic diisocyanates); and mixtures of two or more thereof.

A method for producing a terminal isocyanate prepolymer from the above-mentioned bifunctional polyol and the above-mentioned diisocyanate compound may be in accordance with a known method, in an organic solvent or without solvent, NCO / OH = 2/1 to The reaction is possible at any ratio of 1/1. In the present invention, this ratio is 2 to 1.2, preferably 2 to 1.5, the molecular weight of the prepolymer is 1,000 to 5,000, and the NCO% is 1 to 5.
% Is desirable.

The chain extender added to the above-mentioned terminal isocyanate prepolymer as required is a known diamine, that is, an aliphatic diamine (ethylenediamine, hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine, etc.); Formula diamine (isophorone diamine,
Dicyclohexylmethane-4,4'-diamine, isopropylidene dicyclohexyl-4,4'-diamine,
1,4-diaminocyclohexane and the like); and a mixture of two or more thereof, and preferred examples include isophoronediamine, hexamethylenediamine, diaminobenzene, 4,4-diaminophenylmethane and the like. Further, already known low molecular weight diols (ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.) and mixtures of two or more of the above diamines and low molecular weight diols are also used as chain extenders. Can be used. These chain extenders are NCO / NH _{2 based on the} terminal isocyanate prepolymer.
It is preferably used in the range of (OH) = 1 / 0.6 to 1 / 0.98.

Examples of the terminal blocking agent used as needed include monoamines such as monoethylamine and di-n-butylamine; monoalcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; hydroxyl monoamines such as monoethanolamine and diethanolamine. To be

Solvents used in the reaction include alcohols such as ethanol, isopropyl alcohol and n-butyl alcohol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; aromatic hydrocarbons such as toluene; tetrahydrofuran; Examples thereof include ethers such as dioxane and a mixture thereof, and isopropyl alcohol, n-butyl alcohol, methyl ethyl ketone, toluene, ethyl acetate and a mixture thereof are preferable in terms of solubility and economy.

The urethane resin used in the present invention can be produced by the following known methods. For example, an organic diisocyanate and a high molecular weight diol are reacted in an excess molar ratio of isocyanate to form a urethane prepolymer having terminal isocyanate groups, the urethane prepolymer is diluted with a solvent to prepare a solvent solution of the urethane prepolymer, and then a chain extender. The method can be carried out by adding a terminating agent after the chain extension by, or by adding an organic diisocyanate, a polymeric diol and a chain extender in a solvent solution in a single step and then adding the terminating agent.

A catalyst may be used for the reaction of polyurethane, and examples of such a catalyst include tertiary amine catalysts such as triethylamine and dimethylaniline, and metal catalysts such as tin and zinc compounds.

A printing ink can be produced using the polyurethane resin as described above by kneading and dispersing various pigments and a solvent in the urethane resin. The composition is generally 10 to 50 parts of pigment and 6 to 1 of binder.
5 copies. If necessary, additives (antiblocking agents, plasticizers, etc.) and resins such as cellulose, maleic acid resins, vinyl chloride-vinyl acetate copolymers can be used in combination.

Printed films to be used for extrusion lamination of polyolefin using printing ink include nylon film (abbreviated as NY), polyester film (abbreviated as PET), biaxially oriented polypropylene film (abbreviated as OPP). (Abbreviation) and the like.

This is not necessary when the printing ink specified in the present invention is printed on the entire surface of the film to be printed, but when a non-printed portion is included, a transparent ink (medium) containing no coloring agent such as pigment is used. However, it is necessary to print on the non-printed part or overprint on the entire surface.

Extrusion lamination of molten polyolefin can be carried out by a known method, but extrusion of polyethylene can be carried out under the above conditions without using an anchoring agent.

[0022]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, Comparative Examples and Test Examples, but the present invention is not limited thereto. All parts and% in the examples are based on weight.

(Synthesis 1 of Resin for Ink) In a round bottom flask equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introducing tube, Polytail HA [manufactured by Mitsubishi Kasei Kogyo Co., Ltd.,
4,400 parts (2 mol) of a hydroxyl value-converted molecular weight of about 2,200 were charged and the temperature was raised to 70 ° C. with stirring. At the same temperature,
After adding 504 parts (3 mol) of hexamethylene diisocyanate and reacting for 7 hours while flowing a nitrogen gas, methyl ethyl ketone and toluene were added in an amount of 5,9.
While adding 10 parts each, the mixture was cooled to 50 ° C. and uniformly dissolved. To this, 136 parts (0.8 mol) of isophoronediamine was added and reacted at the same temperature of 50 ° C. for 7 hours, and further 29 parts (0.4 mol) of diethylamine was added.
The reaction was carried out for a time to obtain a urethane resin having a nonvolatile content of 30%.

(Synthesis example 2 of resin for ink) Polytail HA [manufactured by Mitsubishi Kasei Kogyo Co., Ltd., was added to a round bottom flask equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introducing tube.
2,200 parts (1 mol) of hydroxyl value-converted molecular weight of about 2,200 and 3,000 parts (1 mol) of caprolactone diol (about 3,000 of hydroxyl value-converted molecular weight) were charged and heated to 70 ° C. with stirring. . At the same temperature, 504 parts (3 mol) of hexamethylene diisocyanate was added and reacted for 7 hours while flowing nitrogen gas, and then cooled to 50 ° C. while adding 6,850 parts of methyl ethyl ketone and toluene. , And evenly dissolved. here,
136 parts (0.8 mol) of isophoronediamine was added and reacted at 50 ° C. for 7 hours at the same temperature.
(Mol) diethylamine was added and reacted for 2 hours to obtain a urethane resin having a nonvolatile content of 30%.

(Synthesis example 3 of resin for ink) In a round bottom flask equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introduction tube, 6,000 parts (2 moles of caprolactone diol (molecular weight in terms of hydroxyl value: about 3,000)) ) Was charged and the temperature was raised to 70 ° C. with stirring. At the same temperature, 504 parts (3 mol) of hexamethylene diisocyanate was added and reacted for 7 hours while flowing nitrogen gas, and then cooled to 50 ° C. while adding 7,780 parts of methyl ethyl ketone and toluene. , And evenly dissolved. To this, 136 parts (0.8 mol) of isophoronediamine was added and reacted at the same temperature of 50 ° C. for 7 hours, and further, 29 parts (0.4 mol) of diethylamine was added and reacted for 2 hours to obtain a nonvolatile content. 30% urethane resin was obtained.

(Ink Formulation Examples) Inks A to D shown in Table 1 were prepared using the above-mentioned ink resin, chlorinated PP resin, titanium oxide, methyl ethyl ketone, toluene and isopropyl alcohol.

(Compounding Example of Diluting Solvent) A diluting solvent shown in Table 1 was prepared using methyl ethyl ketone, ethyl acetate, toluene and isopropyl alcohol.

OPP in the following examples and comparative examples
As a film, FOR (manufactured by Nimura Chemical Co., Ltd., 2
0 μ), E5100 (12 μ) manufactured by Toyobo Co., Ltd. as a PET film, and Emblem (15 μ manufactured by Unitika Ltd.) as a NY film.

The polypropylene extrusion lamination uses FL25HA (MFR: 21 manufactured by Mitsubishi Petrochemical Co., Ltd.) as a polypropylene resin, the resin temperature is 280 ° C., the laminating speed is 100 m / min, and the lamination thickness is 20 μ. As Petrosen 203 (Made by Tosoh Corporation, M
FR: 8) was used, the resin temperature was 320 ° C., the laminating speed was 150 m / min, and the laminating thickness was 20 μ. In addition, in the following Examples and Comparative Examples, when the developed product was placed on the developed product, the developed product was stuck on the OPP film for lamination.

Example 1 Ink A was printed with a diluting solvent to give a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds) and the color was spread on the OPP film by using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 2 Ink A printing viscosity with diluting solvent (1 with Zahn cup # 3
It was adjusted to 5 seconds) and the color was developed on the PET film by using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 3 Ink A was printed with a diluting solvent (1 in Zahn cup # 3).
It was adjusted to 5 seconds), and the NY film was developed using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 4 Ink B was printed with a diluting solvent (1 in Zahn cup # 3).
It was adjusted to 5 seconds) and the color was spread on the OPP film by using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 5 Ink B was printed with a diluting solvent to obtain a printing viscosity (1 in Zahn cup # 3).
It was adjusted to 5 seconds) and the color was developed on the PET film by using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 6 Ink B was printed with a diluting solvent to give a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds), and the NY film was developed using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 7 Printing viscosity of Ink A with diluting solvent (Zahn cup # 3 1
It was adjusted to 5 seconds) and the color was spread on the OPP film by using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 8 Ink A was printed with a diluting solvent (1 in Zahn cup # 3).
It was adjusted to 5 seconds) and the color was developed on the PET film by using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 9 Ink A was printed with a diluting solvent to obtain a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds), and the NY film was developed using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 10 Ink B was printed with a diluting solvent to obtain a printing viscosity (1 in Zahn cup # 3).
It was adjusted to 5 seconds) and the color was spread on the OPP film by using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 11 Ink B was printed with a diluting solvent to give a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds) and the color was developed on the PET film by using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Example 12 Ink B was printed with a diluting solvent to give a printing viscosity (1 in Zahn cup # 3).
It was adjusted to 5 seconds), and the NY film was developed using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

COMPARATIVE EXAMPLE 1 Ink C was printed with a diluting solvent to obtain a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds) and the color was spread on the OPP film by using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

COMPARATIVE EXAMPLE 2 Ink C was printed with a diluting solvent to obtain a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds) and the color was developed on the PET film by using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

COMPARATIVE EXAMPLE 3 Ink C was printed with a diluting solvent to obtain a printing viscosity (Zahn cup # 3: 1).
It was adjusted to 5 seconds), and the NY film was developed using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Comparative Example 4 Ink D was printed with a diluting solvent to obtain a printing viscosity (Zahn cup # 3: 1).
It was adjusted to 5 seconds) and the color was spread on the OPP film by using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

COMPARATIVE EXAMPLE 5 Ink D was printed with a diluting solvent to give a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds) and the color was developed on the PET film by using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Comparative Example 6 Ink D was printed with a diluting solvent to obtain a printing viscosity (Zahn cup # 3: 1).
It was adjusted to 5 seconds), and the NY film was developed using a bar coater # 4. Polypropylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Comparative Example 7 Ink C was printed with a diluting solvent to obtain a printing viscosity (Zahn cup # 3: 1).
It was adjusted to 5 seconds) and the color was spread on the OPP film by using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Comparative Example 8 Ink C was printed with a diluting solvent to obtain a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds) and the color was developed on the PET film by using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Comparative Example 9 Ink C was printed with a diluting solvent to obtain a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds), and the NY film was developed using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Comparative Example 10 Ink D was printed with a diluting solvent to obtain a printing viscosity (Zahn cup # 3: 1).
It was adjusted to 5 seconds) and the color was spread on the OPP film by using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

COMPARATIVE EXAMPLE 11 Ink D was printed with a diluting solvent to give a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds) and the color was developed on the PET film by using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

COMPARATIVE EXAMPLE 12 Ink D was printed with a diluting solvent to give a printing viscosity (1 with Zahn cup # 3).
It was adjusted to 5 seconds), and the NY film was developed using a bar coater # 4. Polyethylene was extruded and laminated on the developed product to obtain a laminate for soft packaging.

Test Example 1 In Examples 1 to 6 and Comparative Examples 1 to 6, at the stage where the inks A to D were developed on the printed film, the adhesiveness of the ink to the film was evaluated by the cellotape test method. The results are shown in Table 2.

Test Example 2 The laminate strength of the laminates obtained in Examples 1-6 and Comparative Examples 1-6 was measured, and the results are shown in Table 2.

Test Example 3 The laminate strength of the laminates obtained in Examples 7 to 12 and Comparative Examples 10 to 12 was measured, and the results are shown in Table 2.

Test Example 4 The amount of residual toluene in the laminates obtained in Examples 7 and 10 and Comparative Examples 7 and 10 was measured, and the results are shown in Table 2.

The evaluation method is as follows. (Laminate strength measurement of polypropylene extrusion lamination)
The lamination strength of polypropylene extrusion lamination was obtained by cutting a laminate film into a tape shape with a width of 15 mm and using Tensilon RTM-25 manufactured by Orientec Co., Ltd. to measure the peel strength by T-type peeling at a speed of 300 mm / min (g / 15 mm ) Units.

(Evaluation of Adhesiveness to PET, NY, OPP (Cellotape Test Method)) After printing on each film, cellotape was attached to the printing surface and rapidly peeled off, and five grades were evaluated according to how much the printed film peeled off. It was (5 (good) ←
-> 1 (evil))

(Measurement of residual toluene) Printed matter (0.1
m ² ) in a 500 ml flask and heated in an oven at 80 ° C. for 30 minutes to vaporize the solvent remaining in the printed matter, collect 1 ml of gas from the flask, and use gas chromatography to remove the residual solvent (mg / M ² ) is measured.

(Measurement of Lamination Strength of Polyethylene Extrusion Lamination) The lamination strength of polyethylene extrusion lamination is 15 mm for a laminate film.
The tape was cut into a strip of width, and using TENSILON RTM-25 manufactured by Orientec Co., Ltd., T at a speed of 300 mm / min.
The peel strength due to mold peeling was measured in units of (g / 15 mm).

[0062]

[Table 1] * Numbers in the table are% by weight * Chlorinated polypropylene: 30% toluene solution, chlorination degree 35, average molecular weight 60,000

[0063]

[Table 2] Note) Delamination: Lamination strength value cannot be obtained due to delamination.

[0064]

According to the manufacturing method of the present invention, the lamination strength of polypropylene extrusion lamination and the adhesion to various printed films can be achieved with one type of printing ink. That is, it is possible to print with one type of ink regardless of what kind of extrusion lamination is applied after printing, and it is effective in improving work efficiency and economic efficiency by reducing the number of times of ink replacement during printing. Further, in polyethylene extrusion lamination, if the printing on the film to be printed is full-screen printing, it is not necessary to use an anchor coating agent, and workability and economy are excellent. Further, compared to the ink containing chlorinated PP as the main binder, less toluene remains, and it also has a sanitary effect.

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Claims (1)

[Claims] 1. A method for producing a packaging material, comprising: printing a film for soft packaging material with a printing ink for laminating; and extruding and laminating a polyolefin film,
A method for producing a packaging material, wherein the main binder of the laminating ink is a urethane resin using a hydrogenated polybutadiene polyol having a terminal hydroxyl group as a polyol component.