JPH10218978A - Polyester resin, polyurethane resin, and adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester resin having a high initial cohesive power, a low vol. shrinkage, and excellent adhesiveness, bonding power, flexibility, etc., a high-performance polyurethane resin produced therefrom, and a high- performance adhesive compsn. produced from the polyurethane resin. SOLUTION: This polyester resin is hydroxyl-terminated, has a number average mol.wt. of 1,000-20,000, and is produced by the polycondensation of a dicarboxylic acid component comprising 10-60wt.% terephthalic acid and 90-40wt.% aliph. dicarboxylic acid with at least one diol component having 2-10 methylene groups. The polyurethane resin is obtd. by reacting the polyester resin with a polyisocyanate compd. and is used for producing the adhesive compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyester resin, a polyurethane resin produced using the polyester resin, and an adhesive composition produced using the polyurethane resin.

[0002]

2. Description of the Related Art Conventionally, a polyurethane resin having a hydroxyl group or an isocyanate group at a molecular terminal obtained by reacting a polyester resin having a hydroxyl group at a molecular terminal with a polyisocyanate compound has a relatively good physical property balance. , Adhesives, sealing agents, paints, etc. (hereinafter simply referred to as “adhesives, etc.”).

[0003] On the other hand, with the recent expansion of applications of the above-mentioned adhesives and the like, polyester resins and polyurethane resins include:
Low volumetric shrinkage, fast crystallization and high initial cohesive strength, final adhesive strength and flexibility, heat resistance, water resistance,
There is a strong demand for a wide range of advanced performances such as excellent weather resistance.

[0004] Various attempts have been made to meet the above demands. For example, in Japanese Patent Application Laid-Open No. 3-86719,
"A method for producing a urethane resin having an isocyanate group at a molecular terminal, characterized by reacting a linear aliphatic saturated polyester diol with polymethylene diisocyanate under polymethylene diisocyanate excess"
Has been proposed.

[0005] However, in the method proposed above, for example, a straight-chain aliphatic saturated polyester diol is obtained by reacting succinic acid having 2 methylene groups with ethylene glycol having 2 methylene groups. When a polyester diol is used, since the polyester diol is liquid at room temperature, the resulting urethane resin and an adhesive using the same have a poor initial cohesive force, and can be applied to applications requiring high performance. There is a problem that there is no.

In the method according to the above proposal, for example, as a linear aliphatic saturated polyester diol, 1,10-decanedicarboxylic acid having 10 methylene groups and 1,10-decanedicarboxylic acid having 10 methylene groups are used. When a polyester diol obtained by reacting with decane diol is used, the polyester diol is solid at normal temperature and is crystallized, so that the obtained urethane resin or adhesive has an excellent initial cohesive force, Poor flexibility,
There is a problem that the volume shrinkage rate becomes high, and the internal strain of the resin layer due to the volume shrinkage easily causes floating or peeling at the interface with the adherend.

Further, in order to cope with the above problems, dicarboxylic acids having 2 to 3 methylene groups and 6 to 10 methylene groups are used as linear aliphatic saturated polyester diols.
Or a diol having a methylene group of 6 to 10 and a diol having a methylene group of 2 to 3 are appropriately selected and reacted. Even if is used, it is necessary to crystallize in order to exert a sufficient initial cohesive force, there is a conflicting problem that the crystallization is poor flexibility, high volume shrinkage, excellent It is difficult to combine the initial cohesion with excellent flexibility.

For example, Japanese Patent Application Laid-Open No. 63-199241 discloses that "an aromatic dicarboxylic acid component in which isophthalic acid and terephthalic acid are mixed in a specific molar ratio, and ethylene glycol and neopentyl glycol in a specific molar ratio. 100 parts by weight of a copolymerized aromatic polyester resin comprising a diol component and a specified amount of a triazine-based amino compound,
And an adhesive composition containing 1 to 20 parts by weight of a polyisocyanate compound as a main component ".

However, in the case of the adhesive composition proposed above, since the aromatic polyester resin as the main component is amorphous, if the glass transition point is lower than room temperature, it lacks initial cohesive strength, and conversely, the glass transition point is low. If the temperature is higher than room temperature, there is a problem that the material becomes hard and brittle and lacks flexibility.

Further, for example, in Japanese Patent Application Laid-Open No. 5-51573, "a crystalline aliphatic polyester diol,
"Hot melt adhesives comprising a urethane resin containing isocyanate groups at both ends obtained by reacting a polyol mixture with an aromatic polyester diol and a diisocyanate" have been proposed.

However, in the case of the hot-melt adhesive proposed above, in order to obtain a sufficient initial cohesion, the ratio of the crystalline aliphatic polyester diol is increased or the glass transition temperature of the aromatic polyester diol is increased. As a result, there is a problem that flexibility is poor, a volume shrinkage rate is large, and floating or peeling is easily generated at an interface with an adherend.

As described above, a polyester resin having both excellent initial cohesive force, a small volume shrinkage, and excellent flexibility, etc., a polyurethane resin produced using the polyester resin, and At present, adhesive compositions and the like produced using the polyurethane resin have not been put to practical use.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention has an excellent initial cohesive force, a small volume shrinkage, and excellent adhesion, adhesion, flexibility and the like. It is an object of the present invention to provide a polyester resin, a high-performance polyurethane resin produced using the polyester resin, and a high-performance adhesive composition produced using the polyurethane resin.

[0014]

The polyester resin according to the invention of claim 1 (hereinafter referred to as "first invention")
A dicarboxylic acid component consisting of 10 to 60% by weight of terephthalic acid and 90 to 40% by weight of an aliphatic dicarboxylic acid and at least one diol component having 2 to 10 methylene groups are obtained by a polycondensation reaction, Further, it has a hydroxyl group at a molecular terminal, and has a number average molecular weight of 1,000 to 20,000.

Further, the polyurethane resin according to claim 2 is
It is obtained by reacting the polyester resin according to the first invention with a polyisocyanate compound.

Further, the adhesive composition according to claim 3 is
It is characterized by being manufactured using the polyurethane resin according to the second invention.

The dicarboxylic acid component used as a raw material of the polyester resin according to the first invention is terephthalic acid 10
-60% by weight and 90-40% by weight of aliphatic dicarboxylic acid
It is necessary to consist of

As described above, by using terephthalic acid and an aliphatic dicarboxylic acid together as a dicarboxylic acid component,
The resulting polyester resin has a structure in which the terephthalic acid molecule, which is an aromatic dicarboxylic acid, is incorporated in the skeleton of the aliphatic polyester diol. It has excellent flexibility.

In the first invention, it is necessary that the aromatic dicarboxylic acid used in combination with the aliphatic dicarboxylic acid is terephthalic acid. When the aromatic dicarboxylic acid is, for example, isophthalic acid, the resulting polyester resin does not have a linear skeleton, and therefore has poor crystallinity and poor initial cohesive strength.

The aliphatic dicarboxylic acid used in combination with the above terephthalic acid is not particularly limited. For example, succinic acid, glutanic acid, adipic acid, suberic acid,
Azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,20-eicosandicarboxylic acid, succinic anhydride, adipic anhydride, azelaine Acid anhydride, 1,10-decanedicarboxylic anhydride, glutamic acid dimethyl ester, suberic acid diethyl ester, sebacic acid dipropyl ester, 1,12-dodecanedicarboxylic acid diethyl ester, 1,20-eicosanedicarboxylic acid dimethyl ester One or more of these are preferably used, and adipic acid is more preferably used.

In the first invention, terephthalic acid, which is an aromatic dicarboxylic acid, is used as a dicarboxylic acid component.
0% by weight, preferably 10 to 80% by weight, and 90 to 40% by weight of the aliphatic dicarboxylic acid, preferably 90 to 20% by weight.
% By weight.

The terephthalic acid is less than 10% by weight;
Alternatively, when the aliphatic dicarboxylic acid exceeds 90% by weight, the resulting polyester resin has a large volume shrinkage or poor flexibility, and conversely terephthalic acid contains 60% by weight.
% By weight or 4% of aliphatic dicarboxylic acids
When the amount is less than 0% by weight, the crystallinity of the obtained polyester resin is reduced, and the initial cohesive strength is poor.

The diol component used as a raw material of the polyester resin according to the first invention has 2 to 2 methylene groups.
It must be at least one diol that is 10.

If the number of methylene groups in the diol exceeds 10, the resulting polyester resin will have high crystallinity and a large volume shrinkage, and will have an adverse effect on the adherend when used as a polyurethane resin or an adhesive composition. Adhesion, flexibility and the like are poor.

The diol having 2 to 10 methylene groups is not particularly restricted but includes, for example, ethylene glycol, 1,3-propanediol,
1,4-butanediol, neopentyl glycol,
Examples thereof include 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, and 1,10-decanediol, which are preferably used.
6-hexanediol is more preferably used.

The above-mentioned diols as diol components may be used alone or in combination of two or more.

The polyester resin according to the first invention has a hydroxyl group at a molecular terminal and has a number average molecular weight of 1,000 to 200.
It must be 00.

The above polyester resin has a number average molecular weight of 1
When the number average molecular weight is less than 20,000, the crystallization speed is remarkably slowed, so that it is difficult to develop the initial cohesion. On the other hand, when the number average molecular weight exceeds 20,000, the viscosity stability of the finally obtained adhesive or the like ( Storage stability) and applicability are reduced.

The method for obtaining a polyester resin having a hydroxyl group at the molecular terminal and having a number average molecular weight of 1,000 to 20,000 is not particularly limited, and a polycondensation reaction of the dicarboxylic acid component and the diol component is carried out by a conventional method. When obtaining the polyester resin, if the charged amount of the dicarboxylic acid component is (n) mol, the charged amount of the diol component is (n +
1) By setting the molar ratio, a hydroxyl group can be provided at the molecular terminal of the obtained polyester resin.

Further, the charged amount (n) mol and (n +
1) When the number average molecular weight of the polyester resin is 1000
The number average molecular weight of the obtained polyester resin is 1000 to 2
0000.

The polyurethane resin according to the second invention is obtained by reacting the polyester resin according to the first invention with a polyisocyanate compound.

As the above polyisocyanate compound,
Although not particularly limited, for example, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate,
Xylylene diisocyanate, cyclohexane phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 1,5
-Naphthalenediisocyanate, 1,5-octylenediisocyanate, etc .;
More than one kind is preferably used, and among them, MDI is more preferably used in terms of safety and ease of handling. still,
The above MDI is purified MDI, crude MDI, liquid modified MD
Any of I may be used.

The reaction ratio between the polyester resin according to the first invention and the above-mentioned polyisocyanate compound is not particularly limited, but is as follows: [isocyanate group (NCO group) in polyisocyanate compound / hydroxyl group (OH group) in polyester resin. It is preferable to carry out the reaction at a ratio such that the molar ratio of (2) becomes 0.2 to 3.

When the molar ratio of the NCO group / OH group is less than 0.2, the molecular weight of the obtained polyurethane resin becomes too large, which impairs the workability and handleability, and conversely, the NCO group / OH group If the molar ratio of the OH groups exceeds 3, the resulting polyurethane resin will have poor cohesive strength and flexibility.

When the molar ratio of the NCO group / OH group is 1 or less, the obtained polyurethane resin has a hydroxyl group at a molecular terminal. Conversely, when the molar ratio of the NCO group / OH group is larger than 1, The resulting polyurethane resin has an isocyanate group at the molecular terminal. Therefore,
By appropriately setting the molar ratio of the NCO group / OH group, a polyurethane resin having a hydroxyl group or an isocyanate group at a molecular terminal can be freely obtained.

The method for producing a polyurethane resin according to the second invention is not particularly limited. For example, under a nitrogen atmosphere,
After heating and melting a predetermined amount of the polyester resin according to the first invention, a predetermined amount of a polyisocyanate compound is added and reacted by a conventional method to obtain a desired polyurethane resin. At this time, a reaction catalyst or a reaction auxiliary such as amines and metal salts may be used as necessary.

The adhesive composition according to the third invention is manufactured using the above-described polyurethane resin according to the second invention.

The form of the adhesive composition according to the third aspect of the present invention is not particularly limited, and a solvent-type adhesive composition obtained by dissolving the polyurethane resin in an organic solvent and a solid polyurethane resin which is heated and melted. Emulsion adhesive composition obtained by emulsifying and dispersing a hot melt adhesive composition, a polyurethane resin in water, self-emulsifying or using an emulsifier, a surfactant or the like, and a liquid polyurethane resin to be used as it is The adhesive composition may be in any form such as a solvent-free liquid adhesive composition. However, in order to sufficiently exhibit the properties of the polyurethane resin according to the second invention, a solvent-based adhesive composition or hot melt It is preferably a mold adhesive composition.

The adhesive composition according to the third aspect of the present invention comprises
Depending on the end groups of the polyurethane resin according to the invention,
It can be used in various ways.

That is, when the polyurethane resin has a hydroxyl group at a molecular terminal, it may be used as a one-part adhesive composition in the above-mentioned various forms, and various properties such as adhesive strength, heat resistance, water resistance, weather resistance and the like. For example, a compound having a functional group capable of reacting with a hydroxyl group such as the above-described polyisocyanate compound may be used as a crosslinking agent and used as a two-part adhesive composition.

When the polyurethane resin has an isocyanate group at the molecular terminal, the above-mentioned various forms may be used as a moisture-curable one-component adhesive composition.
The two-part adhesive composition may be used in combination with a compound having a functional group capable of reacting with an isocyanate group such as a hydroxyl group or an amino group.

The adhesive composition according to the third invention may contain, if necessary, a thermoplastic elastomer, a tackifying resin, an oil, etc. for improving the adhesiveness, as long as the object of the present invention is not hindered. Amine and tin catalysts to enhance the performance; fillers, softeners, plasticizers, surfactants, wetting agents, thickeners, stabilizers, antioxidants, ultraviolet absorbers, coloring agents, etc. One or more of the agents may be contained.

The thermoplastic elastomer is not particularly limited, but includes styrene-conjugated diene block copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, polyolefin, polyester and polyurethane. And one or more of these are preferably used.

The tackifying resin is not particularly limited, but includes rosin resin, terpene resin, styrene resin, cumarone-indene resin, aliphatic petroleum resin, alicyclic petroleum resin, and aromatic resin. Examples thereof include petroleum resins such as petroleum resins, styrene resins, cumarone-indene resins, and the like, and one or more of these are suitably used. The softening point of the tackifier resin is not particularly limited, but is preferably 90 to 150 ° C. as a ring and ball softening point.

The above oil is not particularly limited, but includes aromatic process oil, naphthene process oil, paraffin process oil, liquid paraffin and the like, and one or more of these are suitable. Among them, aromatic process oils are more preferably used.

The use of the adhesive composition according to the third aspect of the present invention is not particularly limited, but includes various uses such as for automobile interiors, building material panels, furniture woodworking, bookbinding, and fiber processing. , Are suitably used for any of these applications. Specific examples of the adherend include, but are not particularly limited to, metals such as iron, copper, aluminum, tinplate, stainless steel, painted steel sheet, zinc steel sheet, polyethylene, polypropylene, acrylic, ABS, and vinyl chloride. , Polycarbonate, nylon, polystyrene, polyurethane and other synthetic resins, wood, plywood, particle board, cardboard,
Examples include various adherends such as paper, nonwoven fabric, and leather, and are suitably used for any of these adherends.

[0047]

The polyester resin according to the first invention condenses a dicarboxylic acid component comprising a specific amount of terephthalic acid (aromatic dicarboxylic acid) and a specific amount of aliphatic dicarboxylic acid with a diol component having a specific number of methylene groups. It is obtained by a polymerization reaction, and the number average molecular weight is in a specific range, so that the initial cohesive force due to crystallization can be quickly expressed, the volume shrinkage is small, and excellent adhesion, adhesive strength, Exhibits flexibility and the like.

Also, the polyurethane resin according to the second invention is
Since it is obtained by reacting the polyester resin according to the first aspect of the invention with a polyisocyanate compound, a hydroxyl group or an isocyanate group can be freely contained at a molecular terminal, and excellent initial cohesive force, small volume shrinkage, and excellent Combines adhesion, adhesion, flexibility, etc.

Further, the adhesive composition according to the third invention comprises:
Since it is manufactured using the polyurethane resin according to the second invention, it can be used in various forms and has excellent initial cohesion, adhesion, adhesion, flexibility, and the like.

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” means “parts by weight”, and “%” means “% by weight” unless otherwise specified.

(Example 1)

(1) Synthesis of polyester resin In a flask equipped with a dehydration circuit, 135 parts of a dicarboxylic acid component comprising 102 parts of adipic acid (aliphatic dicarboxylic acid) and 33 parts of terephthalic acid, and 1,6 as a diol component After charging 118 parts of -hexanediol (methylene group number 6) and adding 0.05 parts of tetraisopropyl titanate as a reaction catalyst, an acid value of 1.0 or less and a water content of 0.1 part were added.
Polycondensation reaction was carried out at 220 ° C. until the content became not more than 06% to synthesize a polyester resin having a hydroxyl group at a molecular terminal. The number average molecular weight of the obtained polyester resin is 22.
The hydroxyl value was 51 KOHmg / g, and the acid value was 0.8.

(2) Synthesis of Polyurethane Resin The polyester resin obtained above was mixed with a 9
After heating and melting at 0 to 150 ° C., 4,4′-diphenylmethane diisocyanate (MDI) is added so that the molar ratio of NCO groups / OH groups becomes 0.8, and the content of NCO groups becomes 0%. To obtain a polyurethane resin which has a hydroxyl group at the molecular end and is solid at room temperature.

(3) Preparation of Adhesive Composition 30 parts of the polyurethane resin obtained above was dissolved in 70 parts of methylene chloride to prepare a solvent-type adhesive composition having a solid content of 30%.

(4) Evaluation The performance of the adhesive composition obtained above (volume shrinkage-
A, adhesive strength-A, flexibility) were evaluated by the following methods. The results were as shown in Table 1.

Volume shrinkage ratio-A The adhesive composition was applied on a glass plate to a thickness of 100 μm.
(Wet), and then left in a 20 ° C. atmosphere for 24 hours to dry. Next, the adhesion of the dried film to the glass plate was visually observed, and the volume shrinkage -A was evaluated according to the following criteria. [Judgment Criteria] ◎ ‥‥ Good adhesion to glass plate, no floating or peeling was observed ○ ‥‥ No floating or peeling from glass plate was observed, but glass was forcibly removed by hand Peeled at the interface with the board △ ‥‥ Partial lifting or peeling was observed × ‥‥ Floating or peeling was observed over the entire surface

Adhesive Strength-A The adhesive composition was applied to a polyvinyl chloride sheet (0.5 mm thick) so that the applied thickness became 100 μm (wet). They were overlapped and roll-pressed at a linear pressure of 3 kg / cm to obtain an adhesion test piece. The obtained adhesive test piece was placed in an atmosphere of 20 ° C. and 65% RH for 2 hours.
After curing for 4 hours, a test piece for measurement was prepared by cutting to a width of 25 mm. Next, the 180-degree peel strength (kgf / 25 mm) of the test piece for measurement was measured at a tensile speed of 50 mm / min. Further, whether the peeling state at this time was cohesive failure or interfacial peeling was visually observed.

After applying the adhesive composition to a flexible steel plate (0.8 mm thick, 10 cm square) so that the applied thickness becomes 200 μm (wet), the adhesive composition is left in an atmosphere of 20 ° C. for 24 hours to dry. Then, a test piece for measurement in which an adhesive composition layer was provided on a steel plate was prepared. Next, the center line of the test piece for measurement was bent into a “H” shape, and the angle at which the adhesive composition layer peeled off from the steel plate surface was measured. It can be said that the smaller the angle is, the better the adhesion to the steel sheet and the more excellent the flexibility.

(Examples 2 to 4 and Comparative Examples 1 to 5) In the synthesis of the polyester resin, the same procedure as in Example 1 was carried out except that the charged compositions of the dicarboxylic acid component and the diol component were changed to the compositions shown in Table 1. Thus, eight types of polyester resins were obtained. The number average molecular weight, hydroxyl value and acid value of the obtained eight types of polyester resins were as shown in Table 1, respectively.

Next, eight kinds of polyurethane resins and an adhesive composition were obtained in the same manner as in Example 1 using the eight kinds of polyester resins obtained above.

The performance of the eight adhesive compositions obtained above was evaluated in the same manner as in Example 1. The results were as shown in Table 1.

Example 5 (1) Synthesis of Polyurethane Resin and Preparation of Adhesive Composition In the synthesis of polyurethane resin, the polyester resin obtained in Example 1 was heated and melted at 90 ° C. in a nitrogen atmosphere. Then, MDI was added so that the molar ratio of NCO group / OH group became 2.0, and reacted for 3 hours to obtain a polyurethane resin having an isocyanate group at a molecular terminal and solid at room temperature. The polyurethane resin obtained above was used as it is as a moisture-curable hot-melt adhesive composition.

(2) Evaluation The performance (solidification time, volume shrinkage-B, adhesive strength-B) of the adhesive composition obtained above was evaluated by the following method. The results were as shown in Table 2.

Solidification time The adhesive composition was heated and melted at 150 ° C.
m), and immediately left in an atmosphere at 20 ° C. after coating so as to have a coating thickness of 100 μm (dry). Next, a corrugated paper (0.5 mm thick) is bonded by finger pressure every 30 seconds after the temperature of the adhesive composition layer reaches 100 ° C., the adhesive composition layer is cooled and solidified, and the corrugated paper is bonded. The time at which it could not be matched was measured and defined as the solidification time (minutes).

Volume shrinkage—B . The adhesive composition was coated on a glass plate to a thickness of 100 μm.
(Dry), and then left in an atmosphere at 20 ° C. for 24 hours. Next, the adhesiveness of the cooled and solidified adhesive composition layer to the glass plate was visually observed, and the volume shrinkage -B was evaluated according to the same criteria as in the case of the volume shrinkage -A.

Adhesive Strength-B After applying the adhesive composition melted at 120 ° C. to a polyvinyl chloride sheet (0.5 mm thick) so that the applied thickness becomes 50 μm (dry), immediately cover material (8 mm thick) is applied. ) And roll-pressed at a linear pressure of 3 kg / cm to obtain an adhesion test piece. After the obtained adhesive test piece was cured in an atmosphere of 20 ° C. and 65% RH for 1 hour, it was cut into a width of 25 mm to prepare a test piece for measurement. Next, at a tensile speed of 50 mm / min, the 180 ° peel strength (kgf / 25 m
m) was measured. Further, whether the peeling state at this time was cohesive failure or interfacial peeling was visually observed.

(Examples 6 to 8 and Comparative Examples 6 to 10)
As shown in Table 2, using the eight types of polyester resins obtained in Examples 2 to 4 and Comparative Examples 1 to 5, eight types of polyurethane resins were synthesized in the same manner as in Example 5, and the obtained eight types of polyurethane resins were obtained. Various types of polyurethane resins were used as they were as moisture-curable hot melt adhesive compositions.

The performance of the eight types of adhesive compositions obtained above was evaluated in the same manner as in Example 5. The results were as shown in Table 2.

[0069]

[Table 1]

[0070]

[Table 2]

As shown in Table 1, each of the solvent-based adhesive compositions of Examples 1 to 4 according to the present invention has a small volume shrinkage and excellent adhesiveness, adhesive strength and flexibility. Have.

On the other hand, a comparative example obtained from a polyester resin synthesized using a dicarboxylic acid component containing no terephthalic acid (Comparative Example 1) or containing less than 10% by weight of terephthalic acid (Comparative Example 2). The solvent-based adhesive composition of Comparative Example 1 or Comparative Example 2 has a large volume shrinkage and is inferior in all of adhesiveness, adhesive strength, flexibility and the like. When the amount of terephthalic acid is 6
The solvent-based adhesive composition of Comparative Example 3 obtained from a polyester resin synthesized using a dicarboxylic acid component exceeding 0% by weight has poor adhesion (cohesion). Furthermore, the solvent-based adhesive composition of Comparative Example 4 obtained from a polyester resin having a number average molecular weight of less than 1000 has poor adhesion (cohesion), and conversely, is obtained from a polyester resin having a number average molecular weight of more than 20,000. The solvent-based adhesive composition of Comparative Example 5 was
Adhesion, adhesive strength, flexibility, etc. are all inferior.

Further, as shown in Table 2, all of the moisture-curable hot melt adhesive compositions of Examples 5 to 8 according to the present invention have a proper setting rate, and thus have good workability. It has excellent initial cohesion, low volumetric shrinkage, and excellent adhesion and adhesion.

On the other hand, a comparative example obtained from a polyester resin synthesized using a dicarboxylic acid component containing no terephthalic acid (Comparative Example 6) or containing less than 10% by weight of terephthalic acid (Comparative Example 7). The moisture-curable hot-melt adhesive composition of Comparative Example 6 or Comparative Example 7 has a too high solidification rate and poor workability, has a large volume shrinkage rate, and is inferior in adhesion and adhesive strength. In addition, the moisture-curable hot melt adhesive composition of Comparative Example 8 obtained from a polyester resin synthesized using a dicarboxylic acid component having a terephthalic acid content of more than 60% by weight has too low a solidification rate and an initial strength. (Initial cohesive strength) and poor adhesion and adhesion. further,
The moisture-curable hot-melt adhesive composition of Comparative Example 9 obtained from a polyester resin having a number-average molecular weight of less than 1000 has too low a solidification rate to have initial strength (initial cohesive strength) and has an adhesive strength (cohesive strength). On the contrary, the moisture-curable hot-melt adhesive composition of Comparative Example 10 obtained from a polyester resin having a number average molecular weight of more than 20,000 has a somewhat large volume shrinkage and poor adhesion and adhesion.

[0075]

As described above, the polyester resin according to the first aspect of the present invention can rapidly develop the initial cohesive force due to crystallization, has a small volume shrinkage, and has excellent adhesiveness, adhesive strength, and good adhesiveness. Since it exhibits flexibility and the like, it is suitably used for various applications including raw materials for synthesizing polyurethane resins.

The polyurethane resin according to the second invention is
Since it is produced using the polyester resin according to the first invention, it is possible to freely contain a hydroxyl group or an isocyanate group at the molecular terminal, and the volume shrinkage is small, and excellent initial cohesive strength, adhesion, adhesive strength, It also has flexibility and the like, and is suitably used for various applications including raw materials for adhesives, sealing agents, paints, and the like.

Further, the adhesive composition according to the third invention comprises:
Since it is manufactured using the polyurethane resin according to the second invention, it can be used in various forms, has a small volume shrinkage, and has excellent initial cohesion, adhesion, and adhesion.
It also has flexibility and the like, and is suitably used for various uses such as for automobile interiors, building material panels, furniture woodworking, bookbinding, and fiber processing.

Claims (3)

[Claims] 1. A dicarboxylic acid component comprising 10 to 60% by weight of terephthalic acid and 90 to 40% by weight of an aliphatic dicarboxylic acid, and at least one having 2 to 10 methylene groups.
Obtained by a condensation polymerization reaction with a kind of diol component, and
It has a hydroxyl group at the molecular end and has a number average molecular weight of 1000 to 2
0000, which is a polyester resin. 2. A polyurethane resin obtained by reacting the polyester resin according to claim 1 with a polyisocyanate compound. 3. An adhesive composition produced using the polyurethane resin according to claim 2.