1. An adhesion promoter for plastisols, characterized in that the adhesion promoter comprises not only a polyaminoamide but also at least 10% by weight, and at most 60% by weight, based on the total weight of adhesion promoter, of ethyldiglycol.
2. The adhesion promoter according to claim 1, characterized in that the proportion of ethyldiglycol is from 25% by weight to 55% by weight, based on the total weight of the adhesion promoter.
3-7. (canceled)
8. The adhesion promoter according to claim 1, characterized in that the proportion of ethyldiglycol is from 40% by weight to 50% by weight, based on the total weight of the adhesion promoter.
9. A plastisol composition comprising an adhesion promoter according to claim 1 and fine-particle polyvinyl chloride or vinyl chloride copolymers.
10. The plastisol composition according to claim 9 further comprising conventional plasticizers, fillers, and additives.
11. The plastisol composition according to claim 9 wherein the adhesion promoter is present in an amount of from 0.3% by weight to 5% by weight, based on the weight of the plastisol composition.
12. The plastisol composition according to claim 11, wherein the adhesion promoter is present in an amount of from 0.5% by weight to 2% by weight, based on the weight of the plastisol composition.
13. The plastisol composition according to claim 12, wherein the adhesion promoter is present in an amount of 1% by weight, based on the weight of the plastisol composition.
14. A method for improving the adhesion of a plastisol composition to a substrate by adding to the plastisol composition an adhesion promoter comprising a polyaminoamide and ethyldiglycol wherein the ethyldiglycol is present in the adhesion promoter in an amount of at least 10% by weight and at most 60% by weight, based on the total weight of adhesion promoter.
15. The method of claim 14, wherein the ethyldiglycol is present in the adhesion promoter in an amount of from 25% by weight to 55% by weight, based on the total weight of the adhesion promoter.
16. The method according to claim 14, wherein the adhesion promoter is added in an amount of from 0.3% by weight to 5% by weight, based on the weight of the plastisol composition.
17. A method for coating a substrate comprising the steps of adding an adhesion promoter according to claim 1 to a plastisol composition comprising fine-particle polyvinyl chloride or vinyl chloride copolymers to form a mixture, homogenizing the mixture, applying the mixture to the substrate, and stoving the substrate at a temperature of from 120\xb0 C. to 160\xb0 C.
18. A process for producing a self-adhesive plastisol by adding an adhesion promoter according to claim 1 to a plastisol composition comprising fine-particle polyvinyl chloride or vinyl chloride copolymers to form a mixture and homogenizing the mixture to form the self-adhesive plastisol.
19. The process according to claim 18 wherein the adhesion promoter is added in an amount of from 0.3% by weight to 5% by weight, based on the weight of the self-adhesive plastisol.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A zoom lens system comprising, in the order from an object side:
(a) a first lens group which has a negative refractive power;
(b) a second lens group which has a positive refractive power; and
(c) a third lens group which has a positive refractive power in the order from the object side,
wherein power of the zoom lens system is varied from a wide-angle end to a telephoto end by changing distances among the lens groups, and
wherein the second lens group has a three-element cemented lens comprising a positive lens c1, a negative lens c2, and a positive lens c3 in the order from the object side.
2. The zoom lens of claim 1, wherein the second lens group comprises the three-element cemented lens and at least one negative lens.
3. The zoom lens of claim 2, wherein the three-element cemented lens satisfies the following conditional expressions:
0.05<nc1\u2212nc2
5<\u03bdc1\u2212\u03bdc2
where nc1 represents refractive index of the lens c1, nc2 represents refractive index of the lens c2, \u03bdc1 represents Abbe’s number of the lens c1, and \u03bdc2 represents Abbe’s number of the lens c2.
4. The zoom lens of claim 2, wherein the three-element cemented lens satisfies the following conditional expressions:
0.05<nc3\u2212nc2
5<\u03bdc3\u2212\u03bdc2
where nc2 represents refractive index of the lens c2, nc3 represents refractive index of the lens c3, \u03bdc2 represents Abbe’s number of the lens c2, and \u03bdc3 represents Abbe’s number of the lens c3.
5. The zoom lens of claim 2, wherein the lens c1 satisfies the following conditional expressions:
1.65<nc1
35<\u03bdc1
where nc1 represents refractive index of the lens c1, and \u03bdc1 represents Abbe’s number of the lens c1.
6. The zoom lens of claim 2, wherein the lens c2 satisfies the following conditional expressions:
nc2<1.70
\u03bdc2<50\u2003\u2003(14)
where nc2 represents refractive index of the lens c2, and \u03bdc2 represents Abbe’s number of the lens c2.
7. The zoom lens of claim 2, wherein the lens c3 satisfies the following conditional expressions:
1.60<nc3\u2003\u2003(17)
40<\u03bdc3\u2003\u2003(18)
where nc3 represents refractive index of the lens c3, and \u03bdc3 represents Abbe’s number of the lens c3.
8. The zoom lens of claim 2, wherein the three-element cemented lens satisfies the following conditional expression:
0.2<fcf2<1.2\u2003\u2003(21)
where fc represents a focal length of the three-element cemented lens, and f2 represents a focal length of the second lens group.
9. The zoom lens of claim 2, wherein at least a lens of the second lens group which is closest to an image side is a plastic lens.
10. The zoom lens of claim 1, wherein the second lens group is composed of the three-element cemented lens.
11. The-zoom lens of claim 10, wherein the three-element cemented lens satisfies the following conditional expressions:
0<nc1\u2212nc2
5<\u03bdc1\u2212\u03bdc2
where n c1 represents refractive index of the lens c1, nc2 represents refractive index of the lens c2, \u03bdc1 represents Abbe’s number of the lens c1, and \u03bdc2 represents Abbe’s number of the lens c2.
12. The zoom lens of claim 10, wherein the three-element cemented lens satisfies the following conditional expressions:
\u22120.05>nc3\u2212nc2
0<\u03bdc3\u2212\u03bdc2
where nc2 represents refractive index of the lens c2, nc3 represents refractive index of the lens c3, \u03bdc2 represents Abbe’s number of the lens c2, and \u03bdc3 represents Abbe’s number of the lens c3.
13. The zoom lens of claim 10, wherein the lens c1 satisfies the following conditional expressions:
1.65<nc1
35<\u03bdc1
where nc1 represents refractive index of the lens c1, and \u03bdc1 represents Abbe’s number of the lens c1.
14. The zoom lens of claim 10, wherein the lens c2 satisfies the following conditional expressions:
1.65<nc2<1.85
\u03bdc2<50
where nc2 represents refractive index of the lens c2, and \u03bdc2 represents Abbe’s number of the lens c2.
15. The zoom lens of claim 10, wherein the lens c3 satisfies the following conditional expressions:
1.70>nc3
65>\u03bdc3
where nc3 represents refractive index of the lens c3, and \u03bdc3 represents Abbe’s number of the lens c3.
16. The zoom lens of claim 10, wherein the lens c3 is a positive meniscus lens with convex surface thereof faced to the object side.
17. The zoom lens of claim 1, wherein the zoom lens satisfies the following conditional expression:
0.9<SD2Y<2.0
where SD represents sum of axial thickness of the lens groups, and 2Y represents a diagonal length of an image-pickup device.